Numbers 19:18-20 New American Bible (Revised Edition) (NABRE)
18 Then someone who is clean will take hyssop, dip it in this water, and sprinkle it on the tent and on all the vessels and persons that were in it, or on the one who touched the bone, the slain person or the other corpse, or the grave. 19 The clean will sprinkle the unclean on the third and on the seventh day, and thus purify them on the seventh day. Then they will wash their garments and bathe in water, and in the evening be clean. 20 [a]Those who become unclean and fail to purify themselves—those people will be cut off from the assembly, because they defile the sanctuary of the Lord. The purification water has not been splashed over them; they remain unclean.