The Talmud (Pesachim 4a) teaches the principle of “zrizin makdimin l’mitzvot”, indicating that it is meritorious to perform a mitzvah at the earliest possible opportunity. The Talmud traces this to the attitude of Avraham prior to the akeidah, and while the Mishnah (Megilah 20b) states that all day is acceptable for daytime mitzvot, Rashi notes that the mitzvot are valid despite the neglecting of “zrizin”. The implication is that the principle is a biblical imperative that had the potential to invalidate the mitzvah, without the Mishnah’s statement. The Turei Even argues against that even being a possibility, leading later sources to understand that he believes “zrizin makdimin l’mitzvot” to be a rabbinical imperative.

Several possibilities exist as to the motivation for “zrizin makdimin l’mitzvot”. On the one hand, it may be a practical consideration, reflecting the fear that a delay will result in the mitzvah opportunity being lost. Alternatively, it may be an enhancement (hiddur) of the mitzvah act, in that it displays enthusiasm for the mitzvah. (It should be noted that there various other phrases in Talmudic literature that promote urgency and timeliness in mitzvah performance, such as “ein ma’avirin al hamitzvot”; “shihuyei mitzvot lo mishaheinan” “chavivah mitzvah b’sha’atah”, etc. These principles may reflect either overlapping or parallel motivations to “zrizin makdimin l’mitzvot” and require separate discussion. See Resp. Panim M’eirot, II, 61) Note, for example, Resp. Noda B’Yehudah (II, Y.D. 166), who decries the practice of greatly delaying a brit that has already missed the eighth day, and identifies as separate concerns the fear that the mitzvah will be lost and “zrizin makdimin l’mitzvot”.

Some sources indicate that after half of the day had passed (chatzot), “zrizin makdimin l’mitzvot” has been forfeited (see Resp. Shvut Ya’akov, in Pitchei Teshuvah, Y.D. 262:2; Levush, O.C. 652; Sefat Emet, Sukkah 38; Pnei Yehosha, Shabbat 9). Such an approach implies that “zrizin makdimin l’mitzvot” is a statement of prioritization, rather than a protective measure, which would dictate acting as early as possible regardless of time of day.

A possibly related question is that posed by many acharonim as to the effect of “zrizin makdimin l’mitzvot” on the mitzvot themselves. Does the “zrizut” become a part of the mitzvah itself, incorporating its rules and status, or is it an additional element separate from the mitzvah itself? There are several indications to the first possibility, including the statement of Tosafot (Megilah 3a, s.v. mevatlin) that delaying the avodah in the Beit HaMikdash would constitute a “bitul” (nullification) of that responsibility (see also Natan Piryo, Nedarim 32a) or that of another Tosafot (Shabbat 130a, s.v. R’ Eliezer) that expediting the process of a brit milah could justify the compromising of laws of Shabbat, just as [8th day] milah itself overrides Shabbat (see also Chatam Sofer, Shabbat 106a).

Alternatively, many sources indicate that “zrizin makdimin l’mitzvot” is a protective measure, as implied by the position of the Terumat HaDeshen (#35) that a minor delay is acceptable as it does not pose a substantial risk (note the objections of Resp. Avodat HaGershuni; Resp. Tzemach Tzedek, 126; Resp. P’nei Yehoshua, E.H. 15).

Many authorities take up the question of what should take precedence when there is a conflict between “zrizin makdimin l’mitzvot” and some other hiddur; in other words, should a mitzvah be done at the earliest possible opportunity, or at its time of most optimal fulfillment? (See Rosh HaShanah 32b; Resp. Shvut Ya’akov, I, 34; Kli Chemdah, Tazria, 3; Chid. Chatam Sofer, Shabbat 134b; Sh’eilat Ya’avetz, I, 35; Moadim U’Zmanim, VII, 192; Biur HaGra, O.C. 426:2 and Magen Avraham 25:2; Torah Temimah, Shemot 12:179). It would seem to follow that if “zrizin makdimin l’mitzvot” is motivated by a fear of losing the mitzvah, such a concern would necessitate haste even when circumstances are not ideal; but if it is meant as an enhancement, it would seem indicated that it is only such when all other optimal elements are in place.

This approach may explain the prevalent practice of holding a brit early in the morning, while a pidyon haben is often held in the afternoon (even if the proper time has arrived earlier). This practice is decried by the Sdei Chemed (ma’arekhet HaPeh, klal 39). It is apparently a concession to the reality of a larger crowd being available in the afternoon, and thus a realization of “b’rov am hadrat Melekh”. However, the same consideration should apply to a brit, and yet “zrizin makdimin l’mitzvot” takes precedence. Based on the above, however, it can be suggested that the “zrizin makdimin l’mitzvot” components of a brit (on the 8th day) and a pidyon haben differ. In the latter case, the motivation is more that of “enhancement”, and thus “zrizin makdimin l’mitzvot” waits for all relevant enhancements to be in place. In the case of the brit, though, there is the additional risk that the 8th day will end, thus forfeiting an integral element of the mitzvah (see Resp. L’Horot Natan, VI, 90). Thus, “zrizin makdimin l’mitzvot” is protective as well, and overrides other enhancements, such as “b’rov am hadrat Melekh”.