There are five things that are prohibited on Tisha Be’av: Eating and drinking, washing (one’s self), rubbing one’s body with oils or body lotions, wearing leather shoes, and marital relations. Our Sages also prohibited learning Torah on Tisha Be’av, for the words of Torah gladden the heart. The only portions of Torah that one may delve into are the book of Iyov (Job), the prophecies regarding the destruction of the Temple in the book of Yirmiya (Jeremiah), the Midrashim regarding the destruction of the Temple, the laws of mourning, and the like.
On Erev Tisha Be’av, one may only eat until close to sunset. The five categories of abstinence we have mentioned above take affect beginning from sunset.
One may not wash his body on Tisha Be’av, either with hot water or cold, or his entire body or just partially. One may not even stick his finger into water. Thus, on the morning of Tisha Be’av, one should wash his hands only until his knuckles the way he washes the rest of the year, i.e. three times on each hand while switching off hands, and recite the blessing of “Al Netilat Yadayim.” After one uses the restroom, he should wash his hands the same way, only until his knuckles.
One should not wash his face on the morning of Tisha Be’av; rather, after one washes his hands, before he dries them while they are still wet; he may brush them over his eyes. If one has eye residue or any other filth in or around his eyes, one may wash the dirty area. If one is extremely concerned about his personal hygiene and does not feel at ease with himself if he does not wash his face in the morning, he may indeed wash his face on the morning of Tisha Be’av.
A new bride who is still within thirty days of her wedding may wash her face on the morning of Tisha Be’av so that she does not become repulsive to her husband.
Regarding the fast of the Seventeenth of Tamuz (and other such public fasts), if it is extremely difficult for one to abstain from brushing his teeth on the morning of the fast, he may be lenient and brush his teeth while taking care not to swallow even a drop of water. Additionally, one must take care not to put a “Revi’it” (81 ml, approximately 2.7 oz.) of water into his mouth at once. Nevertheless, on Tisha Be’av one should not be lenient to do this unless one suffers immensely without doing so or if one suffers from bad breath, in which case one may be lenient on condition that one tilt his mouth downwards, in order that the water not reach his throat (in addition to the aforementioned conditions). Unfortunately, we cannot discuss the reasoning for each of these laws at length in this segment.
By Popular Request: We have already discussed that one may not wear a freshly-laundered garment during the week during which Tisha Be’av falls out. Thus, one must wear any garment which he intends to wear during these days before this week begins for approximately an hour, and in this way the garment will not be considered “freshly-laundered” anymore and it will be permissible to wear it. The question is: If one, for whatever reason, forgot to prepare clothing for this week, is there any way to permit him to wear a freshly-laundered garment during this week? The answer is that the Sefer Lechem HaPanim writes in the name of Hagaon Maharash of Lublin that if one leaves the garment for a short while on uncovered earth, one may wear this garment during the week during which Tisha Be’av falls out, as this is not considered a “freshly-laundered” garment. Maran Harav Shlit”a writes that in a situation where one forgets to prepare clothing for this week, he may rely on this opinion to allow wearing clothing in this way.