All of you who have killed a person or touched the dead are to remain outside the camp for seven days. On the third day and the seventh day you are to purify both yourselves and your captives.

Numbers 19:11
Whoever touches any dead body will be unclean for seven days.

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

Numbers 19:16
Anyone in the open field who touches someone who has been killed by the sword or has died of natural causes, or anyone who touches a human bone or a grave, will be unclean for seven days.

Numbers 31:18
but spare for yourselves every girl who has never had relations with a man.

Numbers 31:20
And purify every garment and leather good, everything made of goat's hair, and every article of wood."

And do you abide without the camp seven days: whoever has killed any person, and whoever has touched any slain, purify both yourselves and your captives on the third day, and on the seventh day.