Numbers 19:9

And a man who is clean shall gather up the ashes of the heifer, and lay them without the camp, in a clean place, and water of sprinkling shall be kept in store for the congregation of Israel. It is a purification.

And a clean man shall gather up the ashes of the heifer, and lay them up in a clean place outside the camp; and they shall be for the congregation of the children of Israel to keep: it is the water of sprinkling, a purification.