Hesabu 31:19

“Ninyi nyote ambao mmeua mtu yeyote au kumgusa mtu yeyote ambaye ameuawa, lazima mkae nje ya kambi kwa muda wa siku saba. Katika siku ya tatu na ya saba lazima mjitakase wenyewe pamoja na wafungwa wenu.

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