7. It is forbidden [on Tish'ah B'av] to wash, with either hot or cold
water. One may not even stick a finger in water. Nevertheless, only washing
for the sake of pleasure is forbidden. Washing that is not intended for
pleasure is permitted. Therefore, one may wash one's hands [upon rising] in
the morning (1). One should, however, be careful to wash only one's fingers
(up to the knuckles), because the main intent of the morning washing is to
remove the "Ruach Ra'ah" ("spirit of impurity") that rests on one's fingers
(2). After drying [one's fingers] slightly, while they are still slightly
moist, one may pass them over one's eyes. If, however, one's eyes are
usually full of muck [in the morning] and one always washes them with
water, one may wash them [on Tish'ah B'av] as well, in the usual manner,
Similarly, if one's hands (or any other part of the body) become soiled
with mud or the like, one may wash off the dirt. After going to the toilet,
one may also wash [the fingers of] one's hands in one's usual manner (3).
Similarly, one may wash one's fingers before the afternoon service (4).
(1) Three times alternatively on each hand.
(2) The Mishna Berura (554:21) notes that the Vilna Gaon questions whether
one can recite the blessing "al netilas yadayim" over this first washing.
Therefore, the Mishna Berura suggests that one says the blessing "al
netilas yadayim" only after one goes to the bathroom and washes his hands
again, in preparation for the morning prayers.
(3) There are those who rule that, in general, if one goes to the toilet
without actually touching oneself (that is, his hands were not exposed to
becoming dirty in any way), then one is not required to wash one's hands
(unless one is about to say the "Sh'mone Esrei"); therefore, according to
these authorities, one would not be allowed to wash one's hands on Tish'ah
B'av, after going to the bathroom without touching oneself. Other
authorities rule that one is required to wash one's hands after going to
the bathroom, even if one's hands were not exposed to becoming dirty,
because one has to say the blessing "asher yatzar", and thus must ritually
cleanse his hands before addressing G-d ("Hicon Likras Elokecho Yisrael").
The later authorities agree that one should go out of one's way to expose
one's hands to becoming dirty in some way when going to the bathroom on
Tish'ah B'av (just touching an area of one's body that is usually covered
is sufficient), in order to become obligated according to everyone to wash
one's hands (See Mishna Berura 554:20 and 613:4).
(4) It is a mitzvah to wash one's hands before praying the "Shmone Esrei"
(silent prayer of 19 blessings), even if they are not dirty, because
praying is considered as if one is standing in G-d's presence. On Yom
Kippur, however, during which there is a Biblical prohibition against
washing, we take into account the authorities who rule that there is no
mitzvah in general to wash hands before praying the "Sh'mone Esrei" (unless
they are dirty, or one has just been to the bathroom), and washing just in
preparation for praying the "Sh'mone Esrei" is prohibited (except before
the morning service, where other reasons apply) (See Mishna Berura 613:5).