433. Can I Get an “Amen?”: The obligation to pray

… Him you shall serve… (Deuteronomy 10:20)

We are commanded in several places to serve God. That could just be one of those general catch-alls that means "do all the mitzvos," but in Deuteronomy 11:13 it specifies to serve God with our hearts. "Service of the heart" is understood to mean prayer (see Talmud Taanis 2a). Even today we use the phrase "avodah she'b'lev" (service of the heart) as a synonym for prayer.

The reason for this mitzvah boils down to God's benevolence. He has provided us with an opportunity to approach Him and to ask for things we feel we may need.

The Biblical obligation to pray does not have set times as our practice is today. The Rambam (Maimonides) maintains that there is a Biblical obligation to pray daily, while the Ramban (Nachmanides) is of the opinion that prayer is only required on an as-needed basis. Nowadays, of course, prayer has been fixed at three times daily, corresponding to the prayers of our Forefathers, Avraham, Yitzchak and Yaakov. Public repetition of the prayer, called the Amidah or Shemoneh Esrei, has been instituted for the morning and afternoon service, corresponding to the daily sacrifices in the Temple (plus an additional service on Shabbos and holidays, corresponding to the Musaf sacrifice). [This is not the conventional explanation, in which the three daily prayer services are said to correspond to the prayers of the Forefathers and/or the daily sacrifices offered in the Temple, without making any distinction between the private and public prayers. See note to Mitzvah #401.]

This mitzvah applies to men and women in all times and places. It is discussed in the Talmud in the third and fourth chapters of tractate Brachos, as well as at the very beginning of tractate Taanis. This mitzvah is codified in the Shulchan Aruch in Orach Chaim 89. It is #5 of the 248 positive mitzvos in the Rambam’s Sefer HaMitzvos and #7 of the 77 positive mitzvos that can be fulfilled today as listed in the Chofetz Chaim’s Sefer HaMitzvos HaKatzar.