The process of purifying a metzora involves taking two live birds and following a detailed procedure with each of them. The Kohen slaughters one bird, while he sets the other bird free. This procedure is unique to the concept of sacrifices, which previously had been applied only to offerings brought and sacrificed upon the Mizbayach, Altar. This is indeed a radical concept that begs elucidation.
Horav Baruch Halevi Epstein, zl, in his Tosefes Brachah gives a noteworthy explanation. Until now, the victim was known as a tamei, impure person. He was an outcast who was relegated to cry out, “Tamei, tamei!” in order to ward off anyone else who might come near him. It was also done to encourage others to pray in his behalf. In any event, he was certainly not the most popular person in town. Now, however, he is released, he is clean, and he may return to society. By sending away the bird free and clear, he is publicly announcing his newly-found freedom. He, however, needs acceptance. All too often, one who has erred and has repented experiences difficulty reentering society. People tend to have long memories. Some do not forget; others do not forgive. This person is no longer confined by the Torah. He should, likewise, no longer be confined by us.