# 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/translate/translate-symaction]])

# wash their clothes

The Levites are supposed to wash their own clothes. You can make clear the understood information. Alternate translation: "then make them wash their clothes" (See: [[rc://en/ta/man/translate/figs-ellipsis]])