What is the procedure for when a baby boy’s eighth day – the day of his Berit Mila – falls on Tisha B’Av, and are any of the restrictions of Tisha B’Ab suspended for the people involved in the Misva?
All people involved in the Berit Mila, even the three "Ba’aleh Berit Abraham" – the father, the Mohel and the Sandak – are bound by all the restrictions that normally apply on Tisha B’Ab. Thus, they may not wear leather shoes or bathe in honor of the occasion. They are, however, allowed to wear Shabbat clothing in honor of the Berit Mila, even though it is generally considered inappropriate to wear Shabbat clothes on Tisha B’Ab. It must be emphasized that although they may wear Shabbat clothes, they are still forbidden from wearing new clothes.
The custom is to delay the Berit Mila until after Hasot (midday as defined by Halacha). The mourning over the Bet Hamikdash is most intense during the morning of Tisha B’Ab, until Hasot, and it is therefore inappropriate to conduct a festive event such as a Berit Mila before Hasot.
Generally, it is customary to smell Besamim with a Beracha at a Berit Mila. When a Berit Mila is performed on Tisha B’Ab, however, Besamim are not used at the Berit.
The Beracha recited over a cup of wine at a Berit Mila is recited even when a Berit is performed on Tisha B’Ab. Of course, the rabbi who recites the Beracha may not drink the wine, and so the wine should be given to the infant’s mother. Women within thirty days after childbirth are exempt from fasting on Tisha B’Ab, and therefore the mother of the child may and should drink the wine over which the rabbi recited the Beracha. She must listen attentively to the rabbi’s Beracha and ensure not to speak until she drinks the wine. If she does not feel like drinking wine, the wine should be given to a minor (child under the age of Bar Misva), as minors are, of course, not obligated to fast.
Summary: When a Berit Mila is performed Tisha B’Ab, the father, Mohel and Sandak are allowed to wear Shabbat clothing, but otherwise all the ordinary restrictions of Tisha B’Ab apply. The Berit Mila should be performed in the afternoon, and not in the morning, and Besamim should not be used. The infant’s mother, who is not obligated to fast (because she is within thirty days after childbirth), should drink from the cup of wine over which the Beracha was recited. If she feels unable to drink, the wine should be drunk by a minor.
