This Halacha is an excerpt from our Sefer
Bathing & Washing one’s skin:
- The general law:
For pleasure: It is forbidden to wash any part of one’s body [for the sake of pleasure] on Tisha B’av. This applies whether with hot or cold water. Even to stick one’s finger in water is forbidden.
To clean dirt: If one’s hand is dirty with mud or feces, it is permitted to wash it with water in order to remove the dirt. Nevertheless, one may only wash the dirty areas and not the entire hand. [The same applies for any part of the body that is dirty.]
For medical purposes: One who is sick may bathe for medical purposes.
Children: Children are not to be bathed on Tisha B’av even if they are below the age of Chinuch, unless they are dirty.
May one wash off sweat from his body if he feels dirty?
- Bathing/washing for the sake of a Mitzvah:
A bride within 30 days: A bride within 30 days after her wedding may rinse her face to beautify herself for her husband.
Mikveh Night on the ninth of Av: A woman whose Mikvah night falls on Tisha B’av, must postpone it until the next night. In such a case, she should perform the Chafifa on the day before Tisha B’av and on the night following Tisha B’av she should again bathe and clean herself, and then immerse.
Hefsek Taharah: A Hefsek Taharah may be performed on Tisha B’av. Nevertheless she is to only slightly wash between her thighs for this purpose. It is permitted to use either hot or cold water.
Washing hands in the morning: Upon awakening on the morning of the 9th of Av one only washes his fingers, up until his knuckles, having intention to remove the impurity which they contain [as on these days the impurity does not extend past the fingers]. [At the conclusion of Tisha B’av, prior to saying Kiddush Levana, one washes his [entire] hand three times inconsecutively.]
Washing hands for the blessing of the Kohanim: A Kohen may wash his [entire] hand prior to the priestly blessings, even if he had already washed them in the morning before prayers, as he is not washing for pleasure purposes.
If one is not fasting, is he to wash hands as usual [until the wrist] when eating bread on Tisha B’av?
May a Levi wash his hands prior to washing the Kohen?
- Washing after bathroom:
When going to the bathroom before Davening, one may wash his fingers [not hand] prior to Davening, even if they did not become dirty in the process. When going to the bathroom during other times, one may only wash his fingers, up to his knuckles, if he got them dirty in the process of going to the bathroom. It is advisable to do so in order to say asher yatzar in purity.
May one wash his entire hands after using the bathroom prior to prayer?
No. One may only wash his hands until his knuckles.
May one wash his fingers three times as usual after using the bathroom before prayer?
May one wash his bottom after using the bathroom?
Yes, one may do so in order to properly remove feces from the area.
If one touched a covered area, or his shoes, may he wash his hands afterwards?
If he is prior to prayer or in the midst of prayer then he may wash his hands up until his knuckle.
- Washing one’s face upon awakening:
Rinsing mucus from one’s eyes: One may wash mucus from his eyes if he is careful to do so throughout the year.
Rinsing the remainder of the face: One may not wash his face, even if he is a very pampered person, unless he has dirt on his face and desires to wash it off.
- Cooling oneself off:
Cooling oneself off with a cold bottle: One may not cool himself down with the cold walls of an open bottle of liquid, due to fear of spillage. [If the bottle is closed and its walls are dry without condensation, it is permitted to use it to cool oneself off.]
Cooling oneself off with a wet towel: One may cool himself down with a dry towel that was wet before Tisha B’av. However, a wet towel is forbidden to use.
- Rinsing the mouth:
It is forbidden to rinse one’s mouth on Tisha B’av. This applies even if one will be using less than a Revius of water. [If, however, this is causing one great discomfort, he may be lenient to rinse his mouth even on Tisha B’av.]
 Michaber 554:7; Admur 613:1 regarding Yom Kippur
 M”B 554:19; Admur 613:1 regarding Yom Kippur
 Michaber 554:9
 The reason: As the bathing prohibition only applies towards bathing for pleasure. [M”B 554:19]
 Admur 613:7
 See Admur 616:3-4 regarding Yom Kippur
 Admur 614:1 regarding Yom Kippur; M”A 614:1; Kaf Hachaim 554:45
 Taz 613:1; Yifei Laleiv 2:4; Mateh Efraim; M”B; Nitei Gavriel 70:5
 Admur 613:18
 Michaber 554:8; Admur 613:21
 Michaber ibid
 M”A 554:10; M”B 554:18; Biur Halacha 551 “Im” based on Shach 199:9 that from the letter of the law the Chafifa must be done on Erev Tisha B’av; Kitzur Dinei Taharah 5:14; Taharah Kehalacha 18:22 and so I received from Harav Asher Lemel Hakohen
Other opinions: Some Poskim rule she is to perform the Chafifa only on Motzei Tisha B’av in a case that she is able to do so. [Rama 551:16; Kitzur SHU”A 122:12; Shiurei Sheivet Haleivi 199:4; Piskeiy Teshuvos 551:47]
 Shaar Hatziyon 551:35 in name of Machatzis Hashekel; Admur 613:21 regarding Yom Kippur; Masas Binyamin 5 brought in Shach Y.D. 381:3; Taz 381:2;
Other opinions regarding Shiva and the same would apply regarding Tisha B’av: Some Poskim rule it is certainly forbidden for a woman to bathe for the sake of performing Hefsek Taharah during Shiva and it is only allowed for her to do so after Shiva, during Shloshim with an irregularity. [Rama Y.D. 381:5 based on Or Zarua Avel] The reason for this is because if immersing for her husband which is a Mitzvah is forbidden, then certainly washing to begin the Shiva Nekiyim is forbidden. [Shach ibid] The Masas Binyamin ibid [brought in Shach and Taz ibid] however negates this ruling of the Rama being that in truth there is no need for her to immerse during Shiva, as she is in any event forbidden to her husband, while starting the Shiva Nekiyim is a Mitzvah. Likewise, the Taz ibid is puzzled by the Rama’s ruling claiming that bathing for non-pleasure purposes is permitted during Shiva. The Taz ibid concludes that in truth even the Rama agrees that she is to perform the Hefsek Taharah during Shiva, and only argues that she is not to bathe herself, as a Hefsek Taharah is valid even without bathing [see Rama 196:3] Practically, the Taz ibid agrees with the ruling of the Masas Binyamin.
 The reason: As this is being done for the sake of a Mitzvah to hasten her going to Mikveh. [Admur ibid]
 Admur 613:2 regarding Yom Kippur; Michaber 554:10 regarding Tisha B’av
Does this ruling apply even according to the Siddur? This ruling is going in accordance to the ruling of the Mahadurah Kama 4:7 that there is no obligation to wash past the fingers. This is opposed to the ruling in the Siddur that one must wash up until the wrist [and thus there is room to say that according to the Siddur even on these days one should wash until his wrist], nevertheless the custom according to all on Yom Kippur and Tisha B’av is not to wash past the fingers, and so ruled the Previous Rebbe. [Rebbe in Shaareiy Halacha Uminhag Vol. 2 page 181]
 Rebbe in Shaareiy Halacha Uminhag Vol. 2 page 182; Ketzos Hashulchan 2 footnote 10
The reason: The reason for this is because the Mekubalim explain that on Yom Kippur the spirit of impurity does not have much power. While on Tisha B’av since there is not much purity on that day, therefore it does not seek much nurture of holiness from the hands, and thus only dissipates to the fingers. [Rebbe ibid] [Alternatively] on Tisha B’av, the entire day belongs to the impure side, and thus the impurity does not care to nurture from such a minute amount of holiness found past the fingers. [Ketzos Hashulchan ibid; brought also in Kaf Hachaim 4:14 and Ben Ish Chay Toldos 2]
Why don’t we wash the entire hand as does a Kohen? The Ketzos Hashulchan ibid asks that although from the impurity perspective there may not be a need to wash past ones fingers on these days, nevertheless being that another [main-Kama] reason for the morning washing is to prepare for prayer:serving G-d like a Kohen, therefore there should still be an obligation to wash the entire hand, as a Kohen must wash his entire hand prior to service. He concludes with a Tzaruch Iyun. [To note however that this question is not only with regards to Yom Kippur, as it should also be asked on the ruling of Kama 4:7 that the everyday washing is only required until the knuckles. To also note from the Siddur that the only reason why Admur require the washing until the wrist is, as he states, “because the impurity dissipates until the wrist”. Thus there is no opinion that says washing the entire hand is required due to exemplifying a Kohen.]
 Rebbe in Shaareiy Halacha Uminhag Vol. 2 page 183
 Kitzur SHU”A 133:4; M”B 613:7; Ketzos Hashulchan 2:10; Luach Kolel Chabad of Grach Naah; Likkutei Sichos 9:386; Yagdil Torah 1 page 318; Hiskashrus 889
Other opinions: Some Poskim rule one is to wash the hands only until the knuckles. [see Misgeres Hashulchan 133:4]
Ruling of Admur in Shulchan Aruch: See Yagdil Torah 1 page 318 in which Rav Bistritzky explains that according to Admur in Shulchan Aruch it is implied that one only needs to wash until his knuckles. Nonetheless, as he concludes there, the Rebbe said to wash entire hand, and so rules Grach Naah in Luach Kolel Chabad and in Ketzos Hashulchan ibid based on Admur ibid.
 Kaf Hachaim 554:53 in name of Tosefes Chaim 155:10
 Mateh Efraim 621:17
 Shevach Hamoadim p. 50 in name of Mahril
 Admur 613:4-5; see M“B 554:21
 Admur 613:4-5; Michaber 613:3; M”B 613:6; Piskeiy Teshuvos 613:2
 Mateh Efraim 613 in Alef Lamteh 7
 Nitei Gavriel 70:2; Piskeiy Teshuvos 613:3; Shearim Hametzuyanim 133:2; Shevet Hakehasi 4:165
 Piskeiy Teshuvos 613:2
 Admur 613:3
 Although from the letter of the law one who is pampered may wash his face, nevertheless the custom is not to do so. [ibid]
 Admur 614:28
 Michaber 567:1 that one may not taste anything on Tisha B’av, even if he will spit out and 567:3 “One who is accustomed to rinse his mouth, it is improper-not Kosher- to do so on a public fast day” based on Terumos Hadeshen 158 regarding the prohibition to taste foods on a fast; Admur 613:7 regarding Yom Kippur; M”A 567:6; Drashos Maharil, brought in Darkei Moshe 567:1 and Elya Raba 567:5 and Kaf Hachaim 567:14; Mamar Mordechai 567:2; Levush 567; Nehar Shalom 567:1; Bigdei Yesha 567:6; Kaf Hachaim 567:13; Chayeh Adam 132:20; Ketzos Hashulchan 2 footnote 25 in name of Ateres Zikeinim; Sefer Haminhagim p. 4 [English]
Stringency or prohibition? It is implied from the Michaber ibid that there is no prohibition from the letter of the law involved in rinsing the mouth even on Yom Kippur, being one has no intent to swallow the liquid and it is merely water. [P”M 567 A”A 6]
 The reason: As one may come to swallow the water. [Mamar Mordechai 567:2; Levush 567, brought in P”M ibid]
 Michaber 567:1
 Chayeh Adam 132:20; M”B 567:11; Kaf Hachaim 567:14