In addition to the special prayers that our forefathers said in times of trouble, they also set times in which they prayed to God (Berakhot 26b). Avraham established Shaĥarit. It was he who first illuminated the world with his faith, and accordingly he established a prayer said while the sun rises. Yitzĥak established Minĥa. He continued on the path of his father Avraham. Sometimes it is easier forge a new path than it is to stay on the same one. Yitzĥak’s strength was that he remained on the path of faith. This corresponds to Minĥa, which expresses continuity, for the whole day is sustained by the power of faith. Yaakov established Ma’ariv because he endured many hardships and vicissitudes, emerging stronger from each and every one. He therefore established the nighttime prayer, since even in the dark, when reality is obscured, it is possible to connect to God and to reveal the supreme eternal light.
Once the patriarchs invented these prayers, there were devout and righteous people who followed in their path and prayed Shaĥarit, Minĥa, and Ma’ariv. As King David said (Tehilim 55:17–18), “As for me, I call out to God, and the Lord saves me. Evening, morning, and noon, I express my grief and moan aloud, and He hears my voice.”
Following the custom of our forefathers, the Men of the Great Assembly established the three prayers, Shaĥarit and Minĥa as obligatory, and Ma’ariv as voluntary. They were instituted to correspond to the communal offerings, since their purpose was to express the inner significance of the sacrifices. Since the morning and afternoon Tamid sacrifices were obligatory, Shaĥarit and Minĥa are obligatory prayers. Ma’ariv corresponds to the burning of the fats and organs on the altar at night. Since failure to bring the latter did not prevent the fulfillment of the mitzva, so too Ma’ariv was also deemed voluntary. However, as time passed, men took upon themselves to recite Ma’ariv as an obligation. On Shabbat, festivals, and Rosh Ĥodesh, we were commanded to bring a musaf sacrifice; hence, the Sages established the recitation of the Musaf prayer to represent it. Women are exempt from praying Musaf (according to most poskim, as detailed below, 2:9).
Since the prayers were instituted to correspond to the sacrifices, the times of the prayers were set according to the times of the offerings (as explained below, 8:1 and 18:1). In the next chapter we will learn which prayers are obligatory for women and which are optional.