Sefer HaChinuch ספר החינוך

That the priests and the Levites work in the Temple in shifts: That the priests and the Levites work in the Temple in shifts (Sefer HaMitzvot, Positive Commandments 36) — meaning to say, in [assigned] groupings — and not that the hand of all be involved together in the work; except for the holidays alone, when all would work together — all who would come would [take part] for the joy of the festival. And elucidated in the book of I Chronicles 24-26, is how David and Shmuel divided them, that they made twenty-four shifts of priests and twenty-four shifts of Levites, in order that each of their shifts could work two weeks a year. And in Tractate Sukkah 55b, they, may their memory be blessed, said that on the festivals, the hand of everyone was equal. And about this is it stated (Deuteronomy 18:6-8), “If a Levite would go, etc.” — and included in the Levite is a priest, since Levi was the father to all of the tribe — “and he will come in all the yearning of his soul. And he will serve in the name of the Lord, his God, like all his brothers, the Levites, who are standing there [...]. A portion like a portion shall they eat.” And the language of Sifrei Devarim 168 is “‘And he will come in all the yearning of his soul’ — perhaps always” — meaning to say, even not on holidays. “[Hence] we learn to say, ‘besides the sales by the fathers’ (Deuteronomy 18:8): that which the fathers sold, this one to that one, ‘you take on your week and I on my week’” — meaning to say, their agreement in the order of the workshifts, each week its shift. And so did the Translation [of Onkelos Deuteronomy 18:8] explain it, “except for the shift that comes on the Shabbat [of a regular week], as so did our fathers ordain.”

It is from the roots of the commandment of known and set shifts [that it is] because all work that is incumbent upon a number of [assigned] men will be done properly, and no laziness or despondency or impatience is found in it. But [regarding] that which is incumbent on the many without there being men [assigned] to do it, sometimes some of them will assign it to others [without their agreement] and sometimes these will be impatient with those about a matter. There is no need to write at length about these things that are well-known about all people in groups. But with a festival, because of the joy [of the festival], they were commanded that the hand of all be equal in them.

From the laws of the commandment is that which they, may their memory be blessed, said (Mishneh Torah, Laws of Vessels of the Sanctuary and Those Who Serve Therein 4:11) that each and every shift would have an appointed man — and he was the head of all of the men of the shift. And he would divide them into households. And on each and every day of the days of the week, the heads of the households would distribute [the jobs, assigning] men to the work, each man his work. And they would change the shifts from one Shabbat day to the next Shabbat day, and rotate accordingly.

And the early prophets established (Mishneh Torah, Laws of Vessels of the Sanctuary and Those Who Serve Therein 6:1-3) that twenty-four shifts of proper and sin-fearing men from the Israelites likewise be appointed. And in every place in the Talmud, they are called the men of [the] watch (anshei maamad); meaning to say they are the agents of Israel, to stand over the communal sacrifices, and like the matter that they, may their memory be blessed, said (Taanit 27a), “Is it possible for the sacrifice of a man to be offered and he not stand over it?” And for every [such] watch, one great [man] would be over them all, and he is called the head of the watch. And this was the custom of the men of the watch: On each and every week, they would gather [and] whoever of them was in Jerusalem or around it, would enter the Temple. But whether in Jerusalem or in the other places, they would gather in the synagogue, pray much, and fast on Monday, Tuesday, Wednesday and Thursday of that week. And the rest of their matters in prayer and in the reading of the Torah is like it is explained in Tractate Taanit and Megillah 22b. And they, may their memory be blessed, said (Sukkah 55a) that the hand of the shifts of priests and Levites was not equal in everything on the festivals, but rather only in the festival sacrifices, the distribution of the bread of display, and the distribution of the two breads of [Shavuot]. But only the shift the time of which is fixed [for then] offers the vows, the oaths and the daily sacrifices, even on the festivals. [That] is to say, “A portion like a portion shall they eat” in the communal sacrifices; but they are not “A portion like a portion” in other things that the fathers already divided and fixed them [for] each and every shift on its week. And a priest (Mishneh Torah, Laws of Vessels of the Sanctuary and Those Who Serve Therein 4:7) that had a sacrifice — behold, he could come to the Temple and offer it at any time he wanted, as it is stated, “and he will come in all the yearning of his soul”; meaning to say he can come to offer a sacrifice that is his at any time that he wants. And the skin is his. [These] and the rest of the details of the commandment are in Tractate Taanit and Megillah and at the end of Sukkah.

And this commandment is practiced by the males of the priesthood and the Levites at the time of the [Temple]. And one who transgresses it and protests against the hand of his fellow, that he not work “in all the yearning of his soul” on the festival, has nullified this positive commandment. And Ramban, may his memory be blessed, differed about this commandment (in Sefer HaMitzvot, Positive Commandments 36) with Rambam, may his memory be blessed, and said that the working of priests in shifts is not understood from the verse at all — like the opinion of the Teacher, may his memory be blessed — but rather it is a law of Moshe from Sinai that they divide the service among themselves into groupings. And Moshe, our teacher, was the one that began to divide them first and he made eight shifts — four from Itamar and his party and four from Elazar and his party. So is the received tradition. And that which the verse stated, “besides the sales, etc.” is a negation, and not a commandment at all; meaning to say that the priests work “in all the yearning of their souls” — whether on weekdays, whether on a festival — except if they want and agree to divide the work among themselves into shifts. And we received as a law to Moshe from Sinai that it is proper to do this, so that the work be done orderly and with alacrity. This is the essence of the words of the Teacher (Ramban), may his memory be blessed.