Standing for a Teacher and Torah scholar:
It is a positive command in the Torah to stand in front of any Torah scholar.
The age of the Sage: The command to stand before a Torah scholar applies even if the Torah scholar is not old but is young and wise. [This applies even if he is a child below the age of Bar Mitzvah.]
The amount of wisdom that defines a Sage: The command to stand before a Torah scholars applies even if the Torah scholar is not one’s teacher. It applies to any Torah scholar who is greater than oneself [in Torah knowledge] and it is fit to learn from him. This, however, only applies to a Torah scholar whose knowledge is excelled far beyond the normal common folk, in which case if the person has more knowledge than oneself, then he is to stand for him. If, however, the person’s knowledge is not excelled far beyond the normal folk, then there is no obligation to stand for him, even though he is more knowledgeable than oneself. Practically, however, today the custom has become to only stand on behalf of the Rosh Yeshiva or Ravad [i.e. head of the Beis Din], although the validity of this custom requires further clarification.
Teacher: One is obligated to stand for his Rebbe. This applies even if he is not his main teacher from whom one has learned majority of his Torah. A teacher, however, is not obligated to stand for his student, even if his student is a very great Torah scholar.
A scholar standing for other scholars: A scholar is not required to stand for another scholar, and it rather suffices to simply show him some form of respect.
A scholar who is not G-d fearing: A scholar who belittles the Mitzvos, and does not have fear of heaven, is considered like the lowest of the common folk [and one is certainly not to stand in respect of him].
Standing for one who is a Baal Mitzvos or is in process of doing a mitzvah: It is permitted even for an exceptional Sage [even if he is the Gadol Hador] to stand in honor of a person who is a man of good deeds [such as charity, philanthropy, Hiddur in Mitzvos]. Some Poskim rule that he is even obligated to stand on his behalf [and certainly the common folk are obligated to stand for a Baal Mitzvos]. [Due to this, it is proper to stand in front of anyone who is performing a Mitzvah in one’s presence, such as a Gabbai Tzedakah when he is collecting money, and so too anyone else who is doing a Mitzvah. Some Poskim hold it is an actual obligation to stand. This, however, only applies if the person is doing a Mitzvah without payment. If, however, he is being paid, then one is not to stand on his behalf.]
Must one stand for the wife of a Torah Sage?
Some Poskim rule one is obligated to stand for the wife of a Torah Sage, just as one is required to stand for the Torah Sage himself. Some Poskim rule this applies even after the death of the Sage. Other Poskim, however, rule that doing so is not obligatory even when her husband is alive, and it is rather an act of piety. Some Poskim write, that according to the Arizal, there is no need to stand for the wife of a Torah sage even as an act of piety. Other Poskim, however, negate this claim.
Must one stand for a scholarly woman?
Must one stand for a blind Torah Scholar?
If one is holding a Chumash in his hands, must he stand up for a Torah scholar?
If one is in the midst of learning Torah, must he stand for a Torah scholar/elder?
Must one stand for a Torah scholar on Tisha Beav?
Must one who is now an adult stand for the person who was his Melammed in Cheder?
If one has vastly exceeded his Melammed in Torah knowledge, then he is not obligated to stand for him. If, however, most of one’s knowledge is from this Melammed, then he is obligated to stand for him just the law by a main teacher. [The Rebbe was witnessed to show much respect to his Melammed in Cheder, Rav Schneur Zalman Vilenkin, even many years later.]
Must one stand in front of the body of a deceased Torah scholar?
Some Poskim rule one is obligated to stand in the presence of a deceased Torah scholar. Other Poskim rule one is not required to stand in the presence of a deceased scholar. According to all opinions, one must stand when a funeral procession is taking place, irrelevant of the scholarly status of the deceased.
In what circumstances must one stand for the Sage/elderly?
Within four Amos: One is obligated to stand for a scholar/elder upon them reaching within one’s four Amos [196 cm]. One is not [i.e. forbidden] to stand in his honor, prior to him reaching within one’s four Amos. The same applies for one’s teacher, if he is not his main teacher from which he learned majority of his wisdom, then he must stand upon him reaching within one’s four Amos.
Rabbo Hamuvhak/Gadol Hador/Ravad/Nassi: One must stand in honor of his main Rebbe [i.e. Rabbo Hamuvhak] upon his Rebbe entering within his sight [even though he is not within four Amos of him]. [This is approximately the distance of 128 meters.] The same law applies towards an exceptional Torah Scholar, even if he is not one’s teacher, one must stand upon him entering within one’s sight. The definition of an exceptional Torah scholar, in this regard, is one who is considered the Gadol Hador and is famous amongst his generation for his wisdom. This refers to a Sage who is exceptionally greater than the other Sages of his generation. The same applies for a Nassi; that one must stand in his honor upon him entering within one’s sight. The same applies for a Rosh Av Beis Din [Ravad], that one must stand on his behalf upon him entering within one’s sight. Some Poskim however rule, that in today’s times we no longer have a concept of a Rosh Av Beis Din.
Riding: If the scholar/elder is riding on a horse, or wagon [or car], and reaches within one’s four Amos, it is considered as if he is walking in one’s four Amos, and one must stand on his behalf.
In the Beis Midrash/Shul/room: When the Nassi enters the Beis Midrash, everyone is to stand for him, and they do not sit down until he tells them to sit down. When the Ravad [i.e., head of Beis Din] enters the Beis Midrash, they make for him two rows through which he walks in-between, and they remain standing until he sits in his place. When a regular Sage enters the Beis Midrash, whoever is within his four Amos upon him walking by, is to stand for him, thus having some people sitting and some people standing, until the Sage reaches his place to sit. [Some Poskim however rule that in today’s times, whenever a Sage or elder enters into a room that is surrounded by walls, everyone in the room must stand for him, even if he is not within one’s four Amos.]
Closing one’s eyes: It is forbidden for one to close his eyes prior to the scholar/elder entering one’s four Amos, simply in order to refrain from needing to stand for him upon him reaching his four Amos.
Bathroom/bathhouse: One is not required to stand for the scholar/elder in a bathroom or bathhouse. This however only applied in the inner room of the bathhouse, however in the outer room [including the middle room in which people change] one is required to stand.
During work: Workers are not obligated to [stop and] stand for a scholar [or elder] while they are working. [If, however, one is self-employed, he may choose to stop his work and stand, if he wishes to be stringent.] If, however, one is working for another [i.e., an employee], it is forbidden for the worker to be stringent upon himself and stand during his work. [This applies even in the presence of one’s main Rebbe.]
Rebbe in presence of his Rebbe: One may not delegate honor to a student in the presence of his Rebbe, unless the Rebbe also delegates respect to the student. This applies even to the student’s student; that the student may not stand in the presence of his Rebbe, when his Rebbe is in the presence of his own Rebbe, unless his Rebbe’s Rebbe also delegates respect to his Rebbe [which is his student].
If one hears the voice of the Sage/elderly, but does not see him, must he stand in his honor?
Some Poskim rule that if one hears the sound of the Sage, or elderly, coming within his vicinity he must stand in his honor.
Who is defined as a Rabbo Hamuvhak, one’s main teacher?
A Rabbo Hamuvhak is defined as any person from whom the student has received majority of his Torah wisdom, whether in Chumash, Mishneh, or Talmud. In today’s times, however, this mainly relates to the Rebbe from whom one learned majority of his knowledge in Halacha, and directed him in the proper path, and not one who taught him the ways of Pilpul and Chakira.
One’s Melammed in Cheder: If most of one’s Torah knowledge is from his Melammed in Cheder, then he is obligated to stand for him, just like a main teacher.
A Maggid Shiur/Shul Rabbi: If most of one’s Torah knowledge comes from the classes given by a certain Rabbi, then this Rabbi is considered his Rabbo Hamuvhak. This applies irrelevant of Torah subject, whether it be Tanach, Gemara, or Halacha.
One who learned majority of his knowledge from Sefarim: One whose majority of knowledge was personally acquired through the study of Sefarim, is not considered to have a Rabbo Hamuvhak, and hence, even one’s primary teacher is only considered a teacher.
If one is sitting on the Bima and a Sage/teacher/elder walk by, must one stand up if he passes within his four Amos, below the Bima?
If one is sitting in a room, and a Sage/teacher/elder walks by in a different room, must one stand up if he passes within his four Amos?
One must stand for a Sage/teacher/elder even if he is in the middle of Davening?
For how long must one remain standing?
Regular Sage/elderly: One must remain standing until the scholar/elder passes from in front of his face. As soon as the scholar [or elder] passes in front of him, he is [i.e. must] to sit down. [Thus, he is to sit down prior to the Sage passing a four Amos distance from him.] Some Poskim however, rule he is to remain standing until the Sage passes a distance of four Amos from him.
Ravad: One must remain standing in honor of the Rosh Av Beis Din until he passes a distance of four Amos from him. Some Poskim, however, rule that in today’s times we no longer have a concept of a Rosh Av Beis Din.
Teacher/Gadol Hador/Nassi: One must remain standing in honor of his main Rebbe [i.e., Rabbo Hamuvhak], and Gadol Hador, and Nassi, until his Rebbe/Gadol/Nassi sits down or until he passes from within his sight. Once his Rebbe [sits], or passes from his sight, he is to sit down.
In a Beis Midrash: See Halacha C!
If the elder/Sage remains standing within one’s four Amos, for how long must one remain standing?
This matter requires further analysis. Seemingly, one should remain standing until the amount of time it takes him to pass from before oneself.
How to stand:
One must fully stand up in front of the scholar/elder with exception to those cases mentioned above in which only slight standing is required.
How often is one required to stand for a Torah Sage?
Some Poskim rule that one is only obligated to stand for his Rebbe twice a day, one time in the morning and a second time in the evening. This, however, only applies in the house of the Rav [i.e. in private], however, in public, when one is in front of others who do not know that he already stood, he is obligated to stand [each time]. [Even in the privacy of the Rebbe’s home, it is permitted for one to stand for his Rebbe more than two times a day if he so wishes, and it is only that he is not obligated to do so. Other Poskim, however, rule one is obligated to stand for his Rebbe even 100 times. Some Poskim rule that this stringency only applies to a Torah scholar and not to an elder. It is questionable if this dispute applies likewise towards standing for one’s parent.]
Avoiding making people stand for you:
It is improper for a Sage to trouble the public, and deliberately pass in front of them, in order so they stand up for him. Rather, he is to take a short path while walking from one area to another in order to diminish the amount of people that need to stand for him. If the Sage is able to walk a different route, and bypass the congregation, it is considered meritorious for him. Alternatively, the Sage is to enter the Shul prior to the congregation. [This mainly applied in previous times when the congregation would sit on the ground, and it was troublesome to make them stand for him. However, today when people sit on benches and there is no trouble involved, one need not be particular in this matter. Although even today, one is not to deliberately walk in front of the congregation in order so they stand for him. However, some Poskim rule that even today one is to specifically take a different route in order not to trouble the congregation to stand, and that so is the custom of the elderly Sages.]
A scholar/elder who forgives his honor:
All [people for whom one is required to stand, such as a Sage; Avad; Gadol Hador; Nassi; elder] if they forgive their honor, then their honor is forgiven [and it is no longer obligatory to stand for them]. Nevertheless, it remains a Mitzvah to honor them and slightly stand up for them. [Some Poskim rule that only a Rav may forgive his respect, however, one who is not a Rav but learns Halacha or Talmud cannot forgive his respect.]
For whom must one stand? One is required to stand in the presence of one’s teacher of Torah, Torah scholar, and elderly person. One is also to stand for the wife of a Torah Sage, a Baal Mitzvos, and one who is performing a Mitzvah. However, the custom of many today is to only stand on behalf of the Rosh Yeshiva or Ravad, although the validity of this custom requires further clarification. If any of the above people forgive their honor, it is no longer obligatory to stand for them, although it still remains a Mitzvah to honor them and slightly stand up for them. One may not delegate honor to a student in the presence of his Rebbe, unless the Rebbe also delegates respect to that student.
Who is defined as a Sage/teacher/elder? A Sage is defined as any G-d fearing person whose Torah knowledge far exceeds that of the common folk. An elder is defined as any Jew who is above 70 years of age, and according to Kabala, above 60 years of age, and is not Rasha. A teacher is defined as anyone who has taught one Torah, even if he did not learn from him majority of his Torah.
When must one stand? One is required to stand upon the above people entering one’s four Amos, whether on foot or in a vehicle, and must remain standing until the person passes from in front of him, in which case he is then to be seated. This is with exception to a main teacher/Gadol Hador/Ravad/Nassi, in which case one must stand upon them entering within his sight, and by a Ravad, must remain standing until he passes a distance of four Amos from him, while by a main teacher/Gadol Hador/Nassi he must remain standing until his Rebbe/Gadol/Nassi sits down, or until he passes from within his sight. Some Poskim however rule that in today’s times we no longer have a concept of a Rosh Av Beis Din. Likewise, one whose majority of knowledge was personally acquired through the study of Sefarim is not considered to have a main teacher. Some Poskim rule that in today’s times, whenever a Torah scholar or elder enters into a room that is surrounded by walls, everyone in the room must stand for him. It is forbidden for one to close his eyes prior to the scholar/elder entering his four Amos, simply in order to refrain from needing to stand for him upon him reaching his four Amos. One is not required to stand for the scholar/elder in a bathroom, or the inner room of a bathhouse. Workers are not obligated to [stop and] stand for a scholar [or elder] while they are working. Even while one is learning Torah he is obligated to stand for [a sage/elder].
How to stand: One must fully stand up in front of the scholar/elder with exception to those cases mentioned above in which only slight standing is required.
How often to stand: In public, one must stand in face of his Rebbe/scholar/elder even 100 times that day. However, in private, it is disputed as to whether one needs to stand more than twice a day, one time in the morning and one time in the evening.
May a Torah scholar belittle himself for the sake of a Mitzvah, such as to play music by a wedding?
It is permitted for a Sage to belittle himself for the sake of Heaven out of service of Hashem and fulfillment of his Mitzvos, such as to rejoice the Chasan and Kallah. According to some Poskim, however, he may not belittle himself for the sake of a Mitzvah Bein Adam Lechaveiro, such as to return a lost object.
 Shulchan Aruch chapter 244; Kiddushin 32b; 244:1
 Michaber ibid; Rambam Talmud Torah 6:1; Sefer Hamitzvos Mitzvas Asei 209; Chinuch Mitzvah 257; Semag 13
The reason: As the verse [Vayikra 19:32] states “Mipnei Seiva Takum”, which means that one is to stand for those who have acquired wisdom.
 Shach 244:1; Perisha; Darkei Moshe; Beis Yosef, all in name of Shivlei Haleket
 Michaber ibid
 Rama ibid; Tur in name of Rambam [or Rameh [see Shach 244:2; See however Beis Yosef and Beir Hagoleh] and Ran
 Shach 244:2; Tosafos; Semak 32; Rosh; Rameh
Other opinions: Some Poskim rule one is only required to stand for a Sage who is excelled far beyond even the Sages of his generation, even if he is more knowledgeable than oneself. [Rif, brought in Shach ibid]
 Shach 244:11
The reason: Seemingly, the reason for this is in order not to differentiate between Sages [and hence avoid offending those people who one thinks is not a Sage], however the Rosh yeshiva or Raavad is a recognizable and undisputable Sage to whom all are to stand for. [Shach ibid]
 Michaber 242:16
 Michaber 242:30
 Shach 242:39 in name of Bach and Derisha
 Michaber 244:8
 Michaber 243:3; Rosh in Teshuvah
 Michaber 244:12; Shabbos 31b
 See Rama 244:10
 The novelty of this ruling is that although in general we prohibit a Sage from doing matters that are beneath his dignity, in this case, it is permitted. [Shach 244:10 in name of Tur; Taz 244:6]
 Shach 244:10 in name of Tur and Ran and Bach; Taz 244:6; The Beis Yosef 244 brings two opinions regarding this matter
Other opinions: Some Poskim rule it is not obligatory to stand for a man of good deeds. [Opinion of Michaber as understood by Bach 244; Birkeiy Yosef 244; Ran; Ramban]
 Ben Ish Chaiy Ki Seitzei 2:19
 Taz 361:2 based on Michaber 361:4 and Tur 361 in name of Maharitz Geios and Yerushalmi who rules that one must stand by funeral because of the Gomlei Chasadim; and based on Kiddushin 33; Tanya chapter 46 “Therefore, the Sages obligated one to stand in front of one who is doing a Mitzvah even if he is a complete ignoramus”
The reason: As Hashem resides and becomes invested in the soul of the Mitzvah performer at the time of performance. [Tanya ibid]
 Ben Ish Chaiy Ki Seitzei 2:19.
 Rama 376:1
 The reason: As standing up in such a state of mourning is not considered a Hiddur. [Shvus Yaakov 3:26] Alternatively, because the Aveilim are busy. [Levush, brought in Gilyon Maharsha 376] The practical ramification is regarding Tisha Beav. [Gilyon Maharsha ibid]
 The Talmud [Shavuos 3b] states that the wife of Rav Huna came to a court case before Rav Nachman and debated whether he should stand for her, despite the fact that doing so may discourage the other party. It is discussed in Poskim as to whether this standing up is from the letter of the law or a Midas Chassidus.
 Taz 242:14 that the positive command to honor a Torah Sage applies also for his wife; Bach 242; Shiyurei Kneses Hagedola 244; Sheilas Yaavetz 2:135; brought in Pischeiy Teshuvah 244:1; See Birkeiy Yosef 244 in name of Bach and Taz 242, and Birkeiy Yosef C.M. 17:5 and Ben Ish Chaiy Ki Seitzei 2:16
 The reason: As Eishes Chaveir Kechaveir, as is proven from the above Gemara. [ibid]
 Taz ibid based on Maharam Mintz; Yaavetz ibid
Other opinions: Some Poskim rule one is not required to honor a Sages wife after his passing. [Taz ibid in name of Tosafos Shavuos Haeidus 36]
 Opinion who argues on Kneses Hagedola, brought in Sheilas Yaavetz ibid; Implication of all Poskim who omitted this ruling from the Shulchan Aruch; See there for a thorough discussion on the matter
 Brought in Birkeiy Yosef 244:1
 Ben Ish Chaiy Ki Seitzei 2:16
 Zera Yitzchak 1 p. 88 that he found a manuscript of the Peri Chadash who left this matter in question, although he rules that one is obligated; Yechaveh Daas 3:72 based on Sefer Chassidim 578 and all Poskim who require standing for an elderly woman, and he concludes that this matter is a Biblical doubt
 Ben Ish Chaiy Ki Seitzei 2:16; Rav Poalim 2 Kuntrus Sod Yesharim 9 based on Arizal in Shaar Hamitzvos Kedoshim; See Halachos Ketanos 1:154 that one is not required to stand for an elderly woman; See Minchas Chinuch 257:3 that according to the Rambam [whom is how we rule] there is no wisdom by a woman, as honoring one’s wisdom only applies if he is commanded to learn it
 Shaar Efraim 78; Ginas Veradim Y.D. 4:1; See Birkeiy Yosef 244; Ben Ish Chaiy Ki Seitzei 2:15
 Sefer Chassidim 930; See Chaim Sheol 71:2; Shiyurei Bracha 244
 The reason: As it is improper for the Torah to stand for those who are learning it. [Chaim Sheol ibid] Alternatively, because one who is involved in a Mitzvah is exempt from another Mitzvah. [Sefer Chassidim ibid]
 Michaber 244:11; Chaim Sheol 71:2
 Shvus Yaakov 1, brought in Pischeiy Teshuvah 242:12
 Machazik Bracha, brought in Pischeiy Teshuvah 242:12
 See Ben Ish Chaiy Ki Seitzei 2:11 in name of Birkeiy Yosef in Shiyurei Bracha
 The reason: As this is a belittling of Torah to stand for an ignoramus. Likewise, if the teacher was paid, it is less respectable to stand for him. [ibid]
 Implication of Taz Y.D. 361:2 based on story in Moed Katan; Pischeiy Teshuvah Y.D. 361:3 based on Taz ibid
 Yad Eliyahu 54, brought in Pischeiy Teshuvah ibid
 Michaber 361:4; Tur 361 based on Yerushalmi and Maharitz Geios
 Michaber 244:2 and 9 and 13-14
 Michaber 244:2; Kiddushin 33a
The reason: One is required to stand in a way that is recognizable to the elder that it is being done out of honor and respect, and it is only recognizable once the person reaches his four Amos. [Taz 244:3; Kiddushin ibid]
 Shach 244:6 and Birkeiy Yosef 244 based on implication of Michaber, as the Michaber 244:2 already taught us that one is not obligated to stand until the Sage reaches the four Amos, so what need is there to repeat this ruling if not for the fact the Michaber is now teaching us that it is even forbidden to stand prior to this point; Ben Ish Chaiy Ki Seitzei 2:13
 Michaber 244:9
The reason: It is forbidden to stand prior to the Sage reaching within one’s four Amos being that it is not recognizable that it is being done in his honor, being that there is no obligation to stand for him yet. [Shach ibid; Birkeiy Yosef ibid]
 Michaber 242:30
Other Poskim: Some rule that one must stand Kimalei Einav for any teacher from which one learned Torah from, even if he did not learn majority of his Torah from him. [Maharik 12]
 This refers to one from who one has learned majority of his Torah from. [Rama 242:4; Michaber 242:30; See Bava Metzia 33; Sheilasos 131]
 Michaber 242:16; 244:9; Kiddushin 33a
 Shach 244:8 in name of Semak 52
 Michaber 244:10
 Rama ibid; Terumas Hadeshen 138; Tosafos
 Shach 244:2
 Michaber 244:14
 Michaber 244:13
 Shach 244:11 based on Semak 32
 Michaber 244:2; 242:16; Kiddushin 33b; Rashi ibid
 Michaber 244:15; Horiyos 12b
 Kneses Hagedola 244 and Birkeiy Yosef 244:5 leaves this matter in question; Ben Ish Chaiy Ki Seitzei 2:13 and in his Sefer Mekabtziel concludes that one must be stringent by a Biblical command.
 The reason: As perhaps in a closed area, the entire area is considered to be within one’s four Amos. Now, although the above law states that only for a Nassi must all the people in the Beis Midrash stand up, perhaps this only applied in previous times, and only in a Beis Midrash was the above order of standing given out, being that only students sat in the Beis Midrash and each day the Nassi/Avaad/Rebbe would enter, and they thus wanted to delegate different levels of respect. However, today, this is no longer applicable. [Birkeiy Yosef ibid]
 Michaber 244:3; Kiddushin 32b
 Michaber 244:4; Kiddushin 32b
 The reason: As the verse states “Stand and honor” from which we learn that only when the standing respects and honors the person, must one stand. [Michaber ibid]
Rabbo Hamuvhak/One’s Rebbe: Some Poskim rule that the above allowance [not to stand] applies even towards one’s main Rebbe, Rabbo Hamuvhak. [Lechem Mishneh Talmud Torah 6, brought in Pischeiy Teshuvah 244:3] Others however rule that it does not apply by one’s main Rebbe, and one is required to stand even in a bathhouse, in respect of his main Rebbe [Turei Even on Rambam ibid, brought in Pischeiy Teshuvah ibid]
 Shach 244:3; see Admur 84:1
 Rama ibid in name of many Rishonim
 Michaber 244:5
 The reason: As the Torah did not obligate one to honor the elderly if doing so will cause one a loss of money. [Kneses Hagedola 244 in name of Mahariy Beiy Rav 52; Birkeiy Yosef 244 in name of Toras Kohanim; Bavli; Yerushalmi]
 Kneses Hagedola 244 in name of Reb Avraham Halevi; Ben Ish Chaiy Ki Seitzei 2:17
 Michaber 244:11; Abayey in Kiddushin 33b; See Chaim Sheol 71:2
 Ben Ish Chaiy Ki Seitzei 2:15
 Michaber ibid
 Rama ibid; Shivlei Haleket
 Gilyon Maharsha 240:7 regarding a father, and 244:1 regarding a Sage or elderly, based on Rama 282:2 that in such a case one must stand for the Sefer Torah even if he does not see it
 Michaber ibid; Baba Metzia 33a
 Rama ibid; Maharik 170
 Ben Ish Chaiy Ki Seitzei 2:11 in name of Birkeiy Yosef in Shiyurei Bracha
 Ben Ish Chaiy ibid
 Ben Ish Chaiy Ki Seitzei 2:20 in name of Binyan Tziyon 83; See also Admur 429:3
 Ben Ish Chaiy Ki Seitzei 2:13
 Ben Ish Chaiy Ki Seitzei 2:13
 Ben Ish Chaiy Ki Seitzei 2:15 in name of Birkeiy Yosef
 Michaber 244:9 and 14-15
 Michaber 244:2 and 9; Kiddushin 33b
 See Shach 244:6 regarding him learning in the Michaber that it is prohibited to stand prior to entering the four Amos, as otherwise the ruling of the Michaber would be repetitive. The same then should apply here regarding this law, as the Michaber already stated this law in 244:2. As for the reason that it is an obligation for one to sit, it is to show that the only reason he stood is in honor of the Sage/elder. [ibid]
 Michaber 244:9
 See Shach 244:7 and Michaber 244:13
 Shach 244:7 in name of Bach; Rashi; Rosh
 Michaber 244:13
 Shach 244:11 based on Semak 32
 Michaber 242:16; 244:9-10 and 14; Based on Yuma 53b; Kiddushin 33a
 Shach 242:35
 Michaber 242:16
 Taz 244:4
 Rama 242:16; See Kiddushin 33b
 Tur in name of Rambam
 The reason: As the honor of his teacher should not be any greater than the honor of Hashem in Kerias Shema. [Taz 242:12]
 Shach 242:36 based on wording of Rama ibid; Bach 242 and Semag 13 who write “not obligated”; however, the Rambam, Tur and other Poskim write “not permitted.” The Rama ibid hence interprets this to mean “not obligated.” [Shach ibid]
 Shach 242:37 in name of Rosh Tur; Levush; Sefer Chassidim 23
 Shevet Halevi 5:130; However, see Sefer Chassidim 23 who writes one must stand for a Zakein even 100 times
 Aruch Hashulchan 240:24 leaves this matter in question; Chayeh Adam 66:7 rules one does not need to stand for a parent more than twice a day, once in the morning and once in the evening.
 Michaber 244:6; Kiddushin 33a
 See Michaber 244:16 “It is not praiseworthy for a Torah Sage to enter last”; See Taz 244:8
 Shach 244:4
 Birkeiy Yosef 244
 Michaber 244:14; Kiddushin 32a
 Chida in Shiyurei Bracha 243
 The reason: As the Torah is not considered his that he can forgive his respect, while by a Rav the Torah is considered already his. [ibid]
 Chavos Yair 202; brought in Shaareiy Teshuvah 244:4
 Rosh brought in Michaber C.M. 263:3