Pidyon ha’ben, like brit milah, is primarily the responsibility of the father. A brit milah must be performed on the eighth day of the child’s birth, unless it would endanger the life of the child. Pidyon ha’ben must be performed on the 31st day of the child’s birth. Neither ceremony may be delayed beyond its prescribed time unless there is some halachic justification to do so.
In the case of milah, such a delay is a very serious matter since the punishment for unjustifiably delaying circumcision, by even one day, is karet, premature death at the hand of God. So important is the duty to circumcise on the eighth day that if the eighth day happens to be Shabbat, the milah is performed even though the surgery involves a melachah de’oreitah, biblically prohibited work on Shabbat.
Accordingly, in the event of a conflict between the duty to circumcise on the eighth day and the prohibition against violating Shabbat by inflicting a wound, the duty to circumcise takes precedence. It is also most important that the circumcision be performed by a devout Jew. So important is this requirement that it takes precedence over the requirement to circumcise on the eighth day. Accordingly, if the only person available to perform the milah on the eighth day is a person who is not a devoutly observant Jew, the milah should be postponed until such a mohel is available.
Unlike a brit milah on the eighth day which overrides the prohibition of performing a melachah on Shabbat, a pidyon ha’ben, which involves the handling of money and the performance of a transaction, both prohibited activities on Shabbat, does not override the Shabbat. Therefore, if the 31st day of the birth is Shabbat, the pidyon ha’ben is postponed to Sunday. Apart from this situation, there is no license to postpone the pidyon ha’ben ceremony beyond its prescribed time. Such a postponement, though not as serious as the postponement of a brit milah, would violate the general prohibition of shihui mitzvah, postponing the performance of a mitzvah.
Both the brit milah and the pidyon ha’ben ceremonies are celebrated by a festive meal, a seudah, to which family and friends are invited. If the 31st day is in the middle of the week, it would of course be more convenient to postpone these ceremonies to Sunday when more guests can attend. Such a postponement is, however, unacceptable for the reasons articulated.
In a situation on which the eighth day is in the middle of the week and the parents insist that the brit milah be performed on a Sunday and threaten to have a non-observant doctor perform the circumcision if the mohel won’t agree to the postponement, then according Rabbi Moshe Feinstein, it is better for the observant mohel agree to perform the circumcision on the Sunday, even though this results in a prohibited delay. The reason for this is that a circumcision performed by a non-observant person is ineffective.
Similarly, if the parents insist that the pidyon ha’ben be performed on a Sunday when more people can attend the seudah, then, notwithstanding the general prohibition of shihui mitzvah, the kohen may perform the ceremony even though it is beyond the 31st day. Of course, in both situations, but especially with milah, the father should be prevailed upon to conduct the ceremony and the celebration at the prescribed time without any postponement.
Both the seudah in honor of the brit milah and in honor of the pidyon ha’ben have the halachic status of seudot mitzvah. This has practical consequences, particularly in the period of the nine days between Rosh Chodesh Av and Tisha B’Av. Accordingly, even though one should refrain from reciting the blessing of Shehecheyanu during the nine days, the blessing may be recited for a pidyon ha’ben performed during that time. Similarly, though one is not permitted to eat meat or drink wine during the nine days, close relatives and friends of the child’s family may do so at a brit or pidyon ha’ben seudah during this time, even on erev Tisha B’Av, provided it is done before noon.
Finally, even though the father of the child may not break his fast when the ninth of Av is on the 31st day of the birth of the firstborn, some authorities hold that when the 31st day of the birth occurs on a Tisha B’Av that was postponed to the 10th of Av (as is the case when the ninth of Av is a Shabbat), the father of the child and the kohen, even though they may not make a se’udat mitzvah, may break their fast in the afternoon.
Raphael Grunfeld’s book “Ner Eyal on Seder Moed” (distributed by Mesorah) is available at OU.org and your local Judaica bookstore. His new book, “Ner Eyal on Seder Nashim & Nezikin,” will be available shortly.