Mishnà su Levitico 14:53

How would they purify a metzora?A new earthenware flask and a quarter of a log of living water was put in it. Two undomesticated birds are also brought. One of these was slaughtered over the earthenware vessel and over the living water. A hole was dug and it was buried in his presence. Cedarwood, hyssop and scarlet wool were taken and bound together with the remaining ends of the strip of wool. Near to these were brought the tips of the wings and the tip of the tail of the second bird. All were dipped together, and sprinkled upon the back of the metzora's hand seven times. Some say that the sprinkling was done upon his forehead. In the same manner one would sprinkle on the lintel of a house from the outside.

He now comes to set free the living bird. He does not turn his face towards the sea or towards the city or towards the wilderness, for it is said, "But he shall let the living bird go out of the city into the open field" (Leviticus 14:53). He now comes to shave off the hair of the metzora. He passes a razor over the whole of his skin, and he [the metzora] washes his clothes and immerses himself. He is then clean so far as to not convey uncleanness by entrance, but he still conveys uncleanness as does a sheretz. He may enter within the walls [of Jerusalem], but must keep away from his house for seven days, and he is forbidden to have intercourse.