Kiddushin 57B

מוקצה ונעבד, דבעלי חיים נינהו ואסירי! כי אסירי ⁠– לגבוה, להדיוט ⁠– מישרא שרי.

the cases of an animal set aside as an offering to an idol, and an animal that was itself worshipped as an idol, which are living creatures and yet are permanently forbidden. The Talmud answers: There is a difference, as when they are forbidden, they are forbidden only to be used for the Most High, i.e., to be used as offerings in the Temple service, but it is permitted for a common Jew to derive benefit from them.

מתקיף לה רבי ירמיה: הרי רובע ונרבע בעדים, דבעלי חיים נינהו ואסירי! אלא: אמר רבי יוחנן משום רבי שמעון בן יוחי: לא מצינו רוב בעלי חיים שאסורים.

R' Yirmeya objects to the explanation of R' Yoḥanan: But an animal that had sex with a woman, and an animal that had sex with a man, in the presence of witnesses, they are living creatures and yet they are permanently forbidden, as the halakha is that these animals are killed, and one is prohibited from deriving benefit from them once they have been sentenced. Rather, the above explanation should be emended to say: R' Yoḥanan says in the name of R' Shimon ben Yoḥai: We have not found most kosher living creatures that are permanently forbidden while they are still alive, and it can be assumed that the inclusion of the verse is referring to that which is generally forbidden, even if there are exceptions.

דבי רבי ישמעאל תנא: דאמר קרא: ״ושלח על פני השדה״⁠ – כשדה, מה שדה מותרת ⁠– אף האי נמי מותרת. האי ״שדה״ להכי הוא דאתא? ההוא מיבעי ליה לכדתניא: ״שדה״⁠ – שלא יעמוד ביפו ויזרקנה לים, בגבת ויזרקנה למדבר, ושלא יעמוד חוץ לעיר ויזרקנה בתוך העיר. אלא כל שעומד בעיר ויזרקנה חוץ לחומה.

The Talmud offers another answer to the question of how the baraita knew which bird the verse is permitting. The school of R' Yishmael taught: The verse states: “And should let go the living bird into the open field” (Leviticus 14:7), which indicates that the bird is like a field: Just as a field is permitted, so too, this bird is also permitted. The Talmud asks: Is that word “field” coming to teach this? That word is necessary for that which is taught in a baraita: The word “field” teaches that one may not stand in Jaffa and throw the bird that is set free to the sea, or stand in Gevat and throw it to the desert, and that he may not stand outside the city and throw it inside the city. Rather, any manner in which he is standing in the city and throws it outside the wall to the field is valid. The word “field” teaches that one must set it free only to the field and nowhere else, not to teach that the bird is permitted.