Rambam - 1 Chapter a Day

It is impossible for the sacrifice of a person to be offered without him standing in attendance. [Now,] the communal offerings are the sacrifices of the entire Jewish people, but it is impossible for the entire Jewish people to stand in the Temple Courtyard at the time they are being offered. Therefore, the prophets of the first era1 ordained that there be selective upright and sin-fearing Jews who should serve as the agents of the entire Jewish people2 to stand [and observe the offering of] the sacrifices. They were called "the men of the maamad."3

They divided them into 24 ma'amadot, equaling the number of watches of the priests and Levites. Over each of the watches was one who was appointed as [the supervisor] of them all. He was called the head of the ma'amad.

Each week, the members of the ma'amad of that week would gather together. Those [living] in Jerusalem or close to it would enter the Temple with the priestly and Levitical watch of that week. When [the week of] their ma'amad arrived, those members of the ma'amad who [lived] in distant places would gather in the synagogues of their locale.

What would those who gather together - both in Jerusalem and in the synagogues - do? They would fast on the Monday, Tuesday, Wednesday, and Thursday of their week. They would not fast on Friday out of respect for the Sabbath4 and not on Sunday, so they would not make a transition from the pleasure of the Sabbath to a fast.5

On every day of the week that was their ma'amad, they would recite four prayer services: the morning service, the afternoon service, the neilah service,6 and another prayer service between the morning service and the afternoon service which was additional [and unique] for them.7 In the ma'amad, the priests bless the people three times, in the morning service, in this additional service, and in the neilah service.8

They would have three men read from the Torah twice a day: in the morning service and in the second service that they would add.9 In the afternoon service, they would not read the Torah. Instead, they would recite [the passages] by heart as one recites the Shema. They would not gather for the afternoon service on Friday, for they were busy [with their preparations] for the Sabbath.

Their gathering together for each of these prayers of these four services and their standing in prayer, supplication, and petition and reading the Torah is called a ma'amad.

What would they read [from the Torah]? The narrative of creation.10 On the first day, they would read: "In the beginning," "Let there be a firmament;"11 On the second day, "Let there be a firmament" and "Let [the waters] be gathered;" on the third day, "Let [the waters] be gathered" and "Let there be luminaries;" on the fourth day, "Let there be luminaries" and "Let the waters teem;" on the fifth day, "Let the waters teem" and "Let the earth produce;" on the sixth day, "Let the earth produce" and "[The heavens and the earth] were completed."

A large passage12 would be read by two men, a small passage, by one. The two passages that were read in the morning would be read during this second service from a scroll. They would then be read again during the afternoon service by heart.

During the eight days of Chanukah, the men of the ma'amad would not carry out a ma'amad13 in the morning service.14 On any day when there was a Musaf sacrifice,15 there was not a ma'amad during their second service, nor in the afternoon service,16 only during the morning and neilah services. On any day when there was a sacrifice of wood,17 there was not a ma'amad during the neilah service, only during the morning, second, and afternoon services.

What was a sacrifice of wood? Certain families had a fixed time on which they would go out to the forests and bring wood for the arrangement [on the altar].18 On the day designated for this family to bring their sacrifices, they would bring voluntary burnt offerings. This was called the sacrifice of the wood. It was like a festival for these families and they were forbidden to have eulogies delivered, fast, and perform work on that day. This was a custom.

Even a private individual who gave wood or logs for the arrangement [of the altar]19 is forbidden to have eulogies delivered, fast, and perform work on that day. This was a custom.

The men of the ma'amad are forbidden to have their hair cut and to launder [their clothes] throughout the week [they serve in the Temple]. On Thursday,20 they were permitted in honor of the Sabbath. Why were they forbidden to have their hair cut and to launder [their clothes]? So that they would not enter their ma'amad while they were unkept. Instead, they would have their hair cut and launder [their clothes] beforehand.21