The question and answer that appear in the Gemara seem odd inasmuch as it is clear that in the case of temurah there is a biblical mandate that the second animal will be affected by the forbidden sanctification. The Sefat Emet suggests that the Gemara was using the example of temurah to make a basic point about Rava’s position. Since in the case of temurahwe see that a forbidden act takes effect, this law should be used as an archetype and we should derive a general principle from it. Rava responds that the case of temurah is unique. The Torah teaches that it is not the forbidden act that grants sanctity to the second animal – the sanctity does not really transfer from one animal to the next – the source of the sanctity is Biblical fiat. Thus Rava’s original concept remains: A forbidden act has no legal effect at all.
Abayye and Rava disagree about a very basic question. When someone performs an action that is forbidden by the Torah, will that action affect reality? The Gemara at the end of yesterday’s daf (=page) teaches:
Said Abayye: Any act which the Divine Law forbids, if it has been done, it has legal effect;for if you were to think that the act has no legal effect, why then is one punishable with lashes? Rava however said: The act has no legal effect at all, and the reason why one is punishable with lashes on account thereof is because one has transgressed a command of the Divine Law.
Today’s daf lists several examples of the performance of forbidden acts whose consequence – or lack of such – are brought to support either Abayye or Rava.
One of the examples that is brought is the case of temurah, where someone tries to exchange a sanctified animal and transfer the holiness to another. In that case, the perpetrator receives lashes and the forbidden act affects the second animal, which becomes sanctified as a result. The Gemara suggests that this disproves Rava’s position. Rava responds by saying that in this case the Torah explicitly states that this will be the consequence of his action.