Leviticus 14:4-6

4he will perform a purification ceremony, using two live birds that are ceremonially clean, a stick of cedar, some scarlet yarn, and a hyssop branch.

5The priest will order that one bird be slaughtered over a clay pot filled with fresh water.

6He will take the live bird, the cedar stick, the scarlet yarn, and the hyssop branch, and dip them into the blood of the bird that was slaughtered over the fresh water.