The prohibition against hitting one’s parents:
One who [as an adult] hits his father or mother during their lifetime ]transgresses a Biblical negative command and] is liable for the death penalty of strangulation. This applies whether to a son or a daughter. [This applies for both a Tumtum and Androgynous.] However, this applies only if blood was drawn through the hit. [This liability for Sekila for cursing one’s parent only applies if the cursing took place in the presence of witnesses and with prior warning.] If, however, blood was not drawn through the hit, then [one is not liable for death, although] it is included within the negative command against hitting any Jew. [If the blood was drawn in the form of an inner wound without it being drawn from the skin, known as a black and blue mark, then the Poskim conclude that one is equally liable.]
Mechila of hitting: A parent cannot give permission to his child to cause him physical pain. Certainly, he cannot forgive his honor to allow his child to hit him or curse him. Thus, if a father forgives his child after he hits or curses him, it does not help to save him from capital punishment.
Causing one’s parent to become deaf: One who hit his parent by their ear and caused them to become deaf is liable for death, as it is not possible that one become deaf without a wound with a drop of blood that is extracted from within the ear and causes him to become deaf.
If one’s parents are Reshaim: [Even] if a person’s father and mother were complete Reshaim and transgressed sins, it still remains forbidden for the son to hit or curse his parent [even though the child is exempt from capital punishment]. This prohibition applies even if the parent was liable for capital punishment and was in the process of being taken out to be killed. However, if one hit or cursed a parent in such a state [of being a Rasha or taken out for capital punishment], then he is exempt from [the death penalty]. If, however, the parents performed Teshuvah, then the son is liable for the death penalty [for hitting or cursing them] even though the parents are in the process of being taken out to be killed.
Giving lashes to one’s parents as an emissary of the court: If a person’s father or mother transgressed a sin for which they are liable to receive lashes, then the son cannot be the one to administer the lashes to his parents even if the son is the appointed executioner of the court.
Harassing and hitting one’s parents as an emissary of the court: A son cannot harass or hit his parents even if the son is the appointed executioner of the court. This applies even if the parents are befitting of receiving this harassment from the court and have not repented.
Shtuki-One who does not know the identity of his father: A person who is Halachically defined as a Shtuki, which is that he does not know the identity of his father even though he knows the identity of his mother, is [nonetheless] liable for hitting and cursing his mother. He is not liable for hitting and cursing his father. This applies even if the mother claims the man to be his father, nonetheless, she cannot cause him to get punished due to her word.
Son or daughter from a gentile woman: A person’s son from a maidservant [i.e., Shifcha Kenanis] or from a Gentile woman [is not considered Jewish and hence] is not liable [for hitting or cursing] his father or mother.
Converts: If a woman converted when she was already pregnant, then the child born is not liable [for hitting or cursing] his father or mother. [Certainly, one who converted is not liable for hitting or cursing his father or mother even if his father or mother also converted.] [Nevertheless] it remains forbidden for a convert to curse or hit or shame his father [or mother] in order so people do not say that his conversion caused him to leave a higher state of holiness to a lower state of holiness. This applies even if his parents are idol worshipers.
Slave [Eved Kenani]: A slave does not have any lineage, and hence his father is not considered like his father for any purpose. Accordingly, even if a slave was emancipated, he is not liable for cursing or hitting his father [or mother] and there is no prohibition involved in doing so any more than any other person.
Goel Hadam: If a father murdered his son, his other children who are the brothers of the victim may not act as the Goel Hadam to murder the father in vengeance.
 Rama 241:1; Rambam Mamarim 5:5; Mishneh Sanhedrin 85b; Shemos 21:15; Pesakim Uteshuvos 241:2; Encyclopedia Talmudit Erech Makeh Aviv Veimo
Can a parent forgive this prohibition and allow himself to be hit by his child? No. [Sheilasos Sheilasa 60; Teshuvas Harivash 220; Maharam Shick Mitzvah 33; Aruch Laner Sanhedrin 84a; Peri Yitzchak 1:54; Chelkas Yaakov Y.D. 131; Minchas Shlomo 1:32; Shevet Halevi 2:112-4; Vol. 5 Kuntrus Hamitzvos 24:2; Betzel Hachochmah 2:55] However, some Poskim are lenient. [Minchas Chinuch Mitzvah 48] Practically, we are stringent unless there are other reasons for leniency in which case this opinion may be joined to the lenient opinion. [Gesher Hachaim 2:1; Chelkas Yaakov Y.D. 131; Minchas Shlomo 1:32; Shevet Halevi 2:112-4]
Not equal to “Hitting G-d”: Regarding hitting a parent it is not possible for it to be equated to G-d being that it is not possible to hit G-d. [Kiddushin 30b]
 Rambam Mamarim 5:5 “This liability for Chenek for cursing one’s parent only applies if the child who cursed his parent is a Gadol and has reached the age of punishment.”
 Rambam Sefer Hamitzvos Mitzvah 319; Minyan Hamitzvos Hilchos Mamrim
 Rambam Mamarim 5:5
 Rama ibid; Rambam Mamarim 5:5 “The above liability only applies if blood was drawn through the hit. If, however, blood was not drawn through the hit, then [one is not liable for death, although] it is included within the negative command against hitting any Jew.”; Sanhedrin 84b; Sheilasos Sheilasa 60; Sefer Hachinuch Mitzvah 48; Yireim 177; Rabbeinu Bechayeh Shemos 21; Mechilta Mishpatim Parsha 5
 Rambam Mamarim 5:5
 Rama ibid; Tur 241; Rambam Mamarim 5:5
 Emek Sheila Sheilas 60:9 in name of Radal; Minchas Yitzchak 1:27; Minchas Shlomo 1:32; Tzafnas Paneiach 2:153; Menachem Meishiv 2:22; See Yerushalmi Sanhedrin 11:1 [leaves in doubt]; See regarding Shabbos: Mishneh Shabbos Chapter 14; Michaber 316
 See Encyclopedia Talmudit ibid footnotes 765-770
 Orchos Chaim Dinei Kibud Av 2; Moshav Zikeinim Vayikra 19:3; Shiyurei Bracha 240:9; Minchas Yitzchak 1:27; Shevet Halevi 2:112-4
 Sheilasos Sheilta Samech based on Sanhedrin 84b; Orchos Chaim Dinei Kibud Av 2; Sefer Chassidim 570; 573-574; Leket Yosher 2:37; Shiyurei Bracha 240:8 Pirush Daled
Other opinions: Some Poskim rule a father can forgive his son to allow him to hit him. [Minchas Chinuch 48:3]
 See Sefer Chassidim 573; Nachal Kadmonim of Chida Pashas Shemos; Birkeiy Yosef 240:13; Encyclopedia Talmudit ibid p. 429 footnotes 774 and 779
 Michaber 241:2; Rambam Mamrim 5:6; Raba in Bava Kama 86a
 Michaber 241:4; Rambam Mamrim 5:12; Sanhedrin 85a
 Rambam Mamarim 6:10
 Rambam Mamarim 6:10
 Michaber 241:5; Rambam Mamrim 5:13; Sanhedrin 85b
 Michaber 241:7; Tur 241; Rambam Mamrim 5:9
 Michaber 241:8; Rambam Mamrim 5:9; Mishneh Yevamos 22a
 The reason: as the child found in the womb of the maidservant or womb of a Gentile woman is similar to an animal found in the womb of an animal. [Taz 241:3]
 Michaber 241:8; Rambam Mamrim 5:9 [regarding father] 10 [regarding mother]; Bava Basra 149a
 The reason for the exemption of the mother: If a woman converted when she was already pregnant, then the child born is not liable for hitting or cursing his mother, as the verse states that one is liable for cursing his father and mother and from here we learn as only one who is liable for hitting and cursing his father is liable for hitting and cursing his mother. [Rambam Mamrim 5:10] Now, as for the reason that a Shtuki is nonetheless liable for cursing his mother even though he does not know his father and is not held liable for doing so, this is because if witnesses would come and testify regarding the identity of his father that he would be liable since the potential liability for cursing his father exists he is therefore liable for cursing and hitting his mother and is not included in the above exemption learned from Scripture. [Kesef Mishneh and Radbaz on Rambam ibid]
 Michaber 241:9; Rambam Mamrim 5:11; Yevamos 22a
 Michaber 241:9; Rambam Mamrim 5:11
 Taz 2401:1; Rambam Mamrim 5:5
 The reason: As after death it is not possible to make a wound in the parent. Accordingly, this ruling does not contradict the fact that a child who wounds a parent who has been found liable for capital punishment is liable for death. [Taz ibid]
 Rambam Mamrim 5:15