Halakha Bilangan 5:3: Mishneh Torah, Negative Mitzvot & Sefer HaChinukh

That a priest who had had an immersion during the day (to cleanse him from his uncleanness) shall not serve in the Sanctuary till after sunset, as it is said, “…. and they shall not profane the name of their God” (Lev. 21:6).^**The permission to serve after sunset can be inferred from Lev. 22:7: “And when the sun is down, he shall be clean, and shall afterwards eat of the holy things, because it is his food.” The prohibition is implied in Lev. 21:6, as above.

That a priest who is unclean shall not enter the courtyard (of the Sanctuary), as it is said, “That they defile not their Camps (in the midst whereof I dwell)” (Num. 5:2-3). This refers to the Camp of the Schechinah (the precincts of the Sanctuary).

The commandment to send the impure out of the camp of the Divine Presence: To send away the impure from the camp of the Divine Presence, as it is stated (Numbers 5:2), “Command the Children of Israel, and they shall send from the camp anyone with an eruption or a discharge and anyone impure of a soul.” And in the wilderness, it was known to them until where was the boundary of the camp of the Divine Presence. And so [too,] in the [future] generations, the Temple and the whole yard which is in front of it is called the camp of the Divine Presence (Zevachim 116b), and it is included in this commandment. And they said in Sifrei Bamidbar 1 that “and they shall send from the camp” is a warning (negative commandment) to the impure not to enter the Temple. And they said in Pesachim 68a, [that] “He shall exit to outside the camp” (Deuteronomy 23:11) is a positive commandment. And this commandment is [indeed] repeated in another place, “If there be among you a man who will not be pure of a nocturnal emission, he shall exit to outside the camp.” And its explanation (Pesachim 68a) is [that it means] outside the camp of the Divine Presence. And, likewise, this itself is repeated, as it went back and stated (Numbers 5:3), “and send them out of the camp.” And I have already written (Sefer HaChinukh 228) that the repetition of prohibitions within a [single] commandment indicates a little bit of the stringency of the commandment; as God wanted for the benefit of His creatures to warn them and go back and warn them about it. [It is like] the way of people that they warn each other many times about all things that have a great need. And if we have nonetheless found [important] bodies of the Torah stated by clues, everything is for a correct reason.