Numbers 16:7
16:7 put fire in them, and set incense on them before the Lord tomorrow, and the man whom the Lord chooses will be holy. You take too much upon yourselves, you sons of Levi!”
Numbers 31:19
Purification After Battle
31:19 “Any of you who has killed anyone or touched any of the dead, remain outside the camp for seven days; purify yourselves and your captives on the third day, and on the seventh day.