Leviticus 14:4; Leviticus 14:7

4 the priest shall command them to take for him who is to be cleansed two live clean birds and cedarwood and scarlet yarn and hyssop.

7 And he shall sprinkle it seven times on him who is to be cleansed of the leprous disease. Then he shall pronounce him clean and shall let the living bird go into the open field.