Midrash for Temurah 17:53
מעיקרא אמר להן ר"ש מן והיה הוא ותמורתו וכי חזא דדרשי רבנן מבהמה בבהמה אמר להם איהו
of a thing which is not his? - One can still maintain that the case is of a consecrated animal belonging to another person and his own hullin and when e.g. , the owner of the consecrated animals says: 'Whoever wishes to exchange with this animal may come and do so'.<span class="x" onmousemove="('comment',' In such circumstances the Biblical text informs us that the substitute is sacred although there is a prohibitory law against the act.');"><sup>38</sup></span>
Sifra
6) "good by bad or bad by good": Whole animals by blemished ones, or blemished ones by whole ones. Whence is it derived that "bad" signifies "blemished"? From (Devarim 17:1) "You shall not sacrifice to the L–rd your G d an ox or a sheep in which there is a blemish, any bad thing." "and if he substitutes substitutes": to include women (in the laws of substitution). "and if he substitutes, substitutes": to include the heir. "beast for beast": one (non-sacred beast) for two (sacred ones), or two (non-sacred ones) for one (sacred one), one for a hundred or a hundred for one. R. Shimon says: (One) beast for (one) beast, and not (one) beast for (many) beasts. They said to him: (One) beast is called a beast, and many beasts are called a beast, as it is written (Yonah 4:11) "and many beast."
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