The time for the mitzvah of circumcision is the eighth day after birth, as it is written:
“On the eighth day, you shall circumcise the flesh of his foreskin.” If a child is not circumcised on the eighth day, the act may fulfill the mitzvah of circumcision, and a blessing is recited, but the mitzvah lacks the distinction of a mitzvah bizmano, a mitzvah performed at the appropriate time. When the mitzvah is performed at the appropriate time, it has a unique quality, as reflected by the fact that it (and all the activities necessary to perform it) supersede the prohibitions against labor on Shabbos as our Sages comment on the above verse. When circumcision is not performed on the eighth day, however, it does not supersede the Shabbos laws.
1. Vayikra 12:3.
2. See the sichah to Parshas Lech Lecha in this series, which explains that in addition to the positive dimension of the mitzvah of circumcision, there is another dimension: it prevents one from being uncircumcised. We cannot, however, say that the blessing is recited because of this factor, because a blessing is not recited over an activity performed to prevent the violation of a prohibition. For example, there are authorities (see Issur ViHeter, Shaar 58, sec. 104) who explain that a blessing is not recited before nikkur, the removal of forbidden fats and blood vessels from meat, because the object of the activity is to prevent transgressions. Accordingly, the fact that a blessing is recited in this instance indicates that the positive dimension of the mitzvah of circumcision is indeed fulfilled even when the circumcision takes place after the eighth day.
3. Shabbos 132a.
