Numbers 9:6-7

9:6 It happened that some men who were ceremonially defiled by the dead body of a man could not keep the Passover on that day, so they came before Moses and before Aaron on that day. 9:7 And those men said to him, “We are ceremonially defiled by the dead body of a man; why are we kept back from offering the Lord’s offering at its appointed time among the Israelites?”

Numbers 9:10

9:10 “Tell the Israelites, ‘If any of you or of your posterity become ceremonially defiled by touching a dead body, or are on a journey far away, then he may observe the Passover to the Lord.

Numbers 19:7

19:7 Then the priest must wash his clothes and bathe himself in water, and afterward he may come into the camp, but the priest will be ceremonially unclean until evening.

Numbers 19:10

19:10 The one who gathers the ashes of the heifer must wash his clothes and be ceremonially unclean until evening. This will be a permanent ordinance both for the Israelites and the resident foreigner who lives among them.

Numbers 19:14

19:14 “‘This is the law: When a man dies in a tent, anyone who comes into the tent and all who are in the tent will be ceremonially unclean seven days.

Numbers 19:17

19:17 “‘For a ceremonially unclean person you must take some of the ashes of the heifer burnt for purification from sin and pour fresh running water over them in a vessel.