Leviticus 14:6-7

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.

7The priest will then sprinkle the blood of the dead bird seven times on the person being purified of the skin disease. When the priest has purified the person, he will release the live bird in the open field to fly away.