Numbers 31:19
And lodge without the host seven days, all that have killed any person and all that have touched any dead body, and purify both yourselves and your prisoners; the third day and the seventh.
Numbers 5:2
"Command the children of Israel that they put out of the host all the lepers and all that have issues and all that are defiled upon the dead;
Numbers 19:11-22
"'He that toucheth any dead person, shall be unclean seven days.
1 Chronicles 22:8
But the word of the LORD came to me, saying, 'Thou hast shed much blood, and hast made many battles. Thou shalt not build a house for my name, for thou hast shed much blood to the earth in my sight.