Sanhedrin 80B

אלא למאן דאמר: זה וזה גורם ⁠– מותר, מאי איכא למימר?

But according to the one who says that in a case where this permitted factor and that forbidden factor cause an outcome to be produced, that outcome is permitted, what can be said? Since deriving benefit from the bull that sired the offspring is permitted, deriving benefit from the offspring should be permitted as well.

אלא אמר רבינא: אימא, אם עד שלא נגמר דינה עיברה וילדה ⁠– ולדה מותר, ואם עד שלא נגמר דינה עיברה ומשנגמר דינה ילדה ⁠– ולדה אסור. עובר ירך אמו הוא.

Rather, Ravina says: Emend the baraita and say that the distinction in the baraita is: If before its verdict was finalized, the cow was impregnated and calved, its offspring is permitted. If before its verdict was finalized, the cow was impregnated and after its verdict was finalized it calved, its offspring is forbidden because the legal status of the fetus is not that of an independent entity; rather, its status is like that of its mother’s thigh, i.e., a part of its body. Therefore, when the mother is sentenced to death, the offspring is also forbidden once it is born.

כל חייבי מיתות, שמע מינה מותרה לדבר חמור ⁠– הוי מותרה לדבר קל.

§ The Mishnah teaches: All those liable to be executed with different court-imposed death penalties who became intermingled are sentenced to the most lenient form of execution. The Talmud notes: Conclude from the Mishnah that an individual who is forewarned for a severe matter is forewarned for a lesser matter. If one is forewarned that if he violates a certain prohibition then he is liable to be stoned, while in fact, he is liable to be executed with a less severe form of execution, the forewarning is effective and he is executed with the less severe form of execution. That is the reason for the halakha in the Mishnah that even those liable to be executed with a more severe form of execution are executed with the less severe form of execution.