en_tn/num/08/07.md

to purify them

Here "them" refers to the Levites.

Sprinkle the water of atonement on them

Moses sprinkling water on them was symbolic of their atonement. Alternate translation: "Sprinkle on their the water that symbolizes atonement" (See: rc://en/ta/man/jit/translate-symaction)

Make them shave their entire body, wash their clothes, and purify themselves

Possible meanings are 1) Moses was to have the Levites shave, wash, and purify, or 2) Moses was to have the Levites purify themselves by shaving and washing, "Make them shave their entire body and wash their clothes; in this way they will purify themselves."