Numbers 8:7

8:7 And do this to them to purify them: Sprinkle water of purification on them; then have them shave all their body and wash their clothes, and so purify themselves.

Numbers 19:12

19:12 He must purify himself with water on the third day and on the seventh day, and so will be clean. But if he does not purify himself on the third day and the seventh day, then he will not be clean.

Numbers 8:6

8:6 “Take the Levites from among the Israelites and purify them.

Numbers 31:24

31:24 You must wash your clothes on the seventh day, and you will be ceremonially clean, and afterward you may enter the camp.’”

Numbers 8:15

8:15 “After this, the Levites will go in to do the work of the tent of meeting. So you must cleanse them and offer them like a wave offering.

Numbers 8:21

8:21 The Levites purified themselves and washed their clothing; then Aaron presented them like a wave offering before the Lord, and Aaron made atonement for them to purify them.

Numbers 19:19

19:19 And the clean person must sprinkle the unclean on the third day and on the seventh day; and on the seventh day he must purify him, and then he must wash his clothes, and bathe in water, and he will be clean in the evening.

Numbers 31:23

31:23 everything that may stand the fire, you are to pass through the fire, and it will be ceremonially clean, but it must still be purified with the water of purification. Anything that cannot withstand the fire you must pass through the water.