869. Greeting Someone on Tisha b'Av
124:12 Marital relations are forbidden on Tisha b'Av. One should be strict even when it comes to touching his wife.
124:13 One may not greet another person on Tisha b'Av. Even to wish someone good morning is prohibited. (It is advisable to inform those who may not know this law as to why we are not greeting them, so they won't be resentful - Mishnah Brurah 554:42.) If one is greeted by a Jew who doesn't know any better, or by a non-Jew, he may return the greeting in a soft voice so as not to be strict with the other person. It is prohibited to send another person a gift on Tisha b'Av because this is considered a form of greeting.