Numbers 31:19
You yourselves will have to keep outside the tent-circle for seven days, anyone of you who has put any person to death or come near a dead body; and on the third day and on the seventh day make yourselves and your prisoners clean.You yourselves will have to keep outside the tent-circle for seven days, anyone of you who has put any person to death or come near a dead body; and on the third day and on the seventh day make yourselves and your prisoners clean.