Leviticus 14:7; Leviticus 14:53

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.

53 And he shall let the live bird go out of the city into the open country. So he shall make atonement for the house, and it shall be clean."