Numbers 19:17
And for an unclean person they shall take of the ashes of the burnt heifer of purification for sin, and running water shall be put thereto in a vessel:
More from Numbers 19
And the LORD spake unto Moses and unto Aaron, saying,
This is the ordinance of the law which the LORD hath commanded, saying, Speak unto the children of Israel, that they bring thee a red heifer without spot, wherein is no blemish, and upon which never came yoke:
And ye shall give her unto Eleazar the priest, that he may bring her forth without the camp, and one shall slay her before
And Eleazar the priest shall take of her blood with his finger, and sprinkle of her blood directly before the tabernacle of the congregation seven times:
And one shall burn the heifer in his sight; her skin, and her flesh, and her blood, with her dung, shall he burn: