Bava Metzia

Not that one is permitted to make an exchange, but that if he did the exchange is valid, and he receives forty [lashes]!  He replied: That accords with R. Judah, who maintained that one is flagellated for [violating] a negative precept which involves no action.  But can you make this agree with R. Judah? Does not the first clause state: All have power to exchange, both men and women. Now, we pondered thereon, what is 'all' intended to add?  [And we answered,] An heir.  And this does not agree with R. Judah: for if it did, surely he maintained that an heir can neither exchange nor lay hands?  — This Tanna agrees with R. Judah in one ruling,  and disagrees in another. Our Rabbis taught: If one muzzles a beast and threshes therewith, he is flagellated, and pays [to the owner of the cow] four kabs in the case of a cow, and three kabs for an ass.  But [is it not a principle], one is not flagellated and executed; nor is one flagellated and made to pay? — Abaye replied: This is in accordance with R. Meir, who maintained, One is flagellated and also made to pay.  Raba said:  The Torah forbade the hire [of a harlot], even if one had relations with his mother.  R. Papa said: He becomes liable for its food from the moment of meshikah,  whereas flagellation is not incurred until muzzling. R. Papa said: The following problems were propounded to me by the disciples of R. Papa b. Abba, and I gave stringent rulings,  one in accordance with the law, the other not in accordance with the law.  They asked of me: May dough be kneaded with milk? And I ruled that it was forbidden, this being in accordance with the law. For it has been taught: Dough may not be kneaded with milk, and if it is, the whole loaf is forbidden, because it may lead to transgression.  Likewise, an oven may not be greased with tail fat,  and if it is, the whole loaf [baked therein] is forbidden, until the oven is heated through.  The other problem they propounded of me was: May two heterogeneous animals [of opposite sexes] be led into a stable?  And I answered them that it is forbidden, this not being in accordance with the law. For Samuel said: In the case of adulterers, they [sc. the witnesses] must have seen them in the posture of adulterers;  but in respect to diverse species, they must have seen him assisting [the copulation] even as [one places the] painting stick in the tube. R. Ahadboi b. Ammi raised an objection: Had Scripture stated, Thou shalt not cause thy cattle to gender,  I might have thought [it to mean], One must not hold a beast when the male [even of its own kind] copulates with it; therefore it is said, with a diverse kind. Surely then this proves that in the case of different species one may not even hold [the female]! — By 'holding', 'assisting' is meant, and why is it designated 'holding'? As a more delicate term. Rab Judah said: In animals of the same species, one may 'assist' [at copulation] even as [one places the painting] stick in the tube, and it is not even forbidden on account of obscenity. Why? Because he is engaged in his work.  R. Ahadboi b. Ammi raised an objection: