Sifra Shemini Chapter 7

¹1) (Vayikra 11:31): "These are what are tamei to you among all that creep": "what are tamei" (rather than just "tamei"): to include their skins (as well as their flesh). I might think (that this refers to) the skins of all of them. It is, therefore, written "These are (the skins of) what are tamei" — the skins of (Vayikra 11:30) the gecko, the land-crocodile, the lizard, and the sand-lizard. R. Yehudah says: The lizard is like the weasel (Vayikra 11:29). R. Yochanan b. Nuria says: Eight sheratzim have skins. ²2) "unclean": to include the egg of the sheretz. I might think (that it is tamei) even if the embryo were not formed; it is, therefore, written (Vayikra 11:29) "in the sheretz" — Just as "sheretz" (implies that) the embryo has been formed, so, the egg. I might think (that this is so) even if the egg is completely closed; it is, therefore, written (Vayikra 11:31) "Everyone who touches them 'will be tamei'" — it must be possible to touch them. How much must it be pierced for this possibility to exist? A hairsbreadth, that it be possible to reach it with a hair. ³3) "are tamei": We are hereby taught that they (these sheratzim) combine with each other (to constitute the requisite amount for tumah): blood with blood, flesh with flesh, blood with flesh, and flesh with blood, whether in one species or in two species. ⁴4) "Everything that touches them will be tamei": to include the handles of vessels (i.e., if the handle touches them, the entire vessel becomes unclean.) But I might think that this is so even (if the sheretz touched a part of the handle) which is greater than the amount (needed for the vessel's manipulation). It is, therefore, written "them" — everything that is needed for their (the vessel's) use. These are the words of R. Akiva. R. Yochanan b. Nuria said to him: Scripture (in "them") speaks of the causer of the tumah (i.e., the sheretz), and you speak of that which becomes tamei (the vessel)! R. Akiva responded (I agree with you.) I understand the verse as "All who touch them (the sheratzim) will be unclean until the evening." One who eats what is tamei and one who drinks what is tamei does not become unclean until the evening, (but only one who touches what is tamei. As to my applying "them" to the vessels, I did so only by way of asmachta [a kind of "support" for what is already understood]). ⁵5) "All who touch them will be tamei": I might think ("all who touch them") when they are alive. It is, therefore, written "in their death." If "in their death," I might think this excludes "in their shechitah." It is, therefore, written "them," even in their shechitah (i.e., their shechitah does not free them of their state of tumah.) How, then, am I to understand "in their death"? In their death, (they confer tumah), and not in their life. ⁶6) "All who touch them": I might think (that he would have to touch all of them (i.e., an entire sheretz, to become unclean.) It is, therefore, written (Vayikra 11:32) "of them" (i.e., even a piece of them). If "of them," I might think that any amount of them (suffices for tumah). It is, therefore, written "them." How is this to be reconciled? He must touch an amount of it that can be considered all of it. The sages estimated this as the size of a lentil. For the sea-lizard is initially of lentil-size. R. Yossi b. R. Yehudah says: (It must be the size of) the tail of a lizard.