Numbers 19:2

19:2 “This is the ordinance of the law which the Lord has commanded: ‘Instruct the Israelites to bring you a red heifer without blemish, which has no defect and has never carried a yoke.

Numbers 19:9

19:9 “‘Then a man who is ceremonially clean must gather up the ashes of the red heifer and put them in a ceremonially clean place outside the camp. They must be kept for the community of the Israelites for use in the water of purification – it is a purification for sin.