If a Kohen has decreed that a Metzora is no longer afflicted with Tzaraat, the Metzora must bring two birds as Korbanot. Rashi, by quoting the midrash, states that the Metzora must bring birds because the his Tzaraat was a result of participation in idle, purposeless chatter, comparable to a bird’s idle, purposeless chirping.
Rav Shlomo Ganzfried asks three questions about the ceremony of bringing the two Korbanot: Why does the process require two birds instead of one? Additionally, why is one bird sacrificed and the other sent free? Furthermore, why is the freed bird released in a field rather than in a city? It was more convenient to release the bird in the city because the Korbanot were given in the Beit HaMikdash, which was closer to the city of Yerushalayim than it was to the surrounding fields.
The following answers are structured around the idea of the Metzora’s understanding of his Korbanot’s purpose, that of encouraging him to repent to prevent becoming a Metzora in the future:
If only one bird had been brought and sacrificed, the Metzora might have reasoned that the bird’s death symbolized the fact that the Metzora should not speak again, preventing him from sinning in the future. However, this assumption is false because HaShem designated ways for the Jews to use the mouth properly, such as saying Brachot. Therefore, a Meztora must bring two birds: one should be sacrificed and one should remain alive to symbolize that the Metzora should continue speaking, but in a proper manner.
However, the Metzora must also realize that in addition to using his mouth in the proper way, he cannot become conceited from his commendable control over his mouth. Accordingly, the second bird is sent away in a field where humble farmers work, reminding the Metzora to prevent haughtiness.
The Ba’al HaTurim explains that the bird that is sacrificed and the bird that is sent free each has its own symbolism. The sacrificed bird symbolizes the Metzora’s overcoming his trait of purposelessly speaking, while the live bird reminds the Metzora that his desire to speak slanderously is still alive. As a result, he must remain strong to prevent his future sins.