Numbers 31:19
Encamp outside the camp seven days. Whoever of you has killed any person and whoever has touched any slain, purify yourselves and your captives on the third day and on the seventh day.
Numbers 5:2
"Command the people of Israel that they put out of the camp everyone who is leprous or has a discharge and everyone who is unclean through contact with the dead.
Numbers 19:11-22
"Whoever touches the dead body of any person shall be unclean seven days.
1 Chronicles 22:8
But the word of the LORD came to me, saying, 'You have shed much blood and have waged great wars. You shall not build a house to my name, because you have shed so much blood before me on the earth.