צַ֚ו אֶת־בְּנֵ֣י יִשְׂרָאֵ֔ל וְאָמַרְתָּ֖ אֲלֵהֶ֑ם אֶת־קָרְבָּנִ֨י לַחְמִ֜י לְאִשַּׁ֗י רֵ֚יחַ נִֽיחֹחִ֔י תִּשְׁמְר֕וּ לְהַקְרִ֥יב לִ֖י בְּמוֹעֲדֽוֹ׃
"Ordonne ceci aux enfants d’Israël et dis-leur: Mes offrandes, ce pain qui se consume pour moi en délectable odeur, vous aurez soin de me les présenter en leur temps.
Tosefta Ta'anit
Moses instituted eight watches for the Priesthood, and eight watches for the Levites. Once David and Samuel the Seer rose up, they made them into twenty-four Priestly watches and twenty-four Levitical watches, as it is said (1 Chr. 9:22), "[David and Samuel the Seer] established them in their office of trust" -- these are the Priestly and Levitical watches. The prophets that were in Jerusalem rose up and affixed there twenty-four posts [of Israelites] corresponding to the twenty-four Priestly and Levitical watches, as it is said (Num. 28:2), "Command the Children of Israel and say to them, My sacrifices, My food ... [you are to be vigilant in offering Me at their appointed time]." It is impossible to say that all of Israel [was tasked with this duty]; rather, it teaches that the agent of a person is like himself.