Numbers 31:19
19All of you, who have killed a person or touched the dead, are to remain outside the camp for seven days. On the third and seventh day, you are to purify [both] yourselves and your captives.
19All of you, who have killed a person or touched the dead, are to remain outside the camp for seven days. On the third and seventh day, you are to purify [both] yourselves and your captives.