Numbers 19
7 Ref And the priest, after washing his clothing and bathing his body in water, may come back to the tent-circle, and will be unclean till evening.
8 And he who does the burning is to have his clothing washed and his body bathed in water and be unclean till evening.
9 Ref Then let a man who is clean take the dust of the burned cow and put it outside the tent-circle in a clean place, where it is to be kept for the children of Israel and used in making the water which takes away what is unclean: it is a sin-offering.
10 Ref And he who takes up the dust of the burned cow is to have his clothing washed with water and be unclean till evening: this is to be a law for ever, for the children of Israel as well as for the man from another country who is living among them.