Midrash su Levitico 7:21

1) (Vayikra 7:21) ("And if a soul touch any thing that is tamei — the tumah of a man, or a beast that is tamei or any abomination that is tamei — and he eat of the flesh of the sacrifice of peace-offerings, which is the L–rd's, then that soul shall be cut off from its people.") I might think that in the area of the consecrated what is tamei can impart tumah to one who is clean, through carrying (i.e., by the one carrying the other); it is, therefore, written "And if a soul touch" — He imparts tumah by touching and not by carrying.

2) "any thing that is tamei": even one who is tamei through (having touched) a dead body (and not by reason of tumah issuing from his own body). "the tumah of a man, or a beast that is tamei, or any abomination that is tamei": If the lesser forms (zav, neveilah, and sheretz) are mentioned (as liable to kareth), why mention the graver form (dead-body tumah)? For if the lesser forms were mentioned and not the graver form, I would say that with the lesser forms he is liable (only) for the tumah of the body (that imparts the tumah) and not for the tumah of the flesh (of the offering), and with the graver form he is liable for both. And if the graver form were mentioned and not the lesser forms, I would say that for the graver form he is liable, but not for the lesser forms. Therefore, both the lesser and the graver must be mentioned.

3) "and he eat of the flesh of the sacrifice of the peace-offerings, which is the L–rd's, then that soul shall be cut off from its people": I might think that there is tumah-kareth liability for peace-offerings alone. Whence do I derive that it obtains for all offerings? From (Vayikra 22:3): "Throughout your generations, every man who draws near of all your seed to (eat) the holy things (… with his uncleanliness upon him, that soul will be cut off before Me.") I might think (that there are included) only what is like peace-offerings, which are eaten for two days and one night. Whence do I derive the same for those offerings that are eaten for one day? From (Vayikra 7:21) "of the flesh of the sacrifice of the peace-offerings." (For without this verse I would say:) This tells me only (of those offerings) whose remnants are eaten. Whence do I derive (for inclusion) a burnt-offering, whose remnants are not eaten? From "the sacrifice." This tells me only of sacrifices. Whence do I derive for inclusion birds and meal-offerings, which are not kinds of sacrifices, (shechitah not obtaining there), until the inclusion (for tumah-kareth liability) of the log of oil of the leper? From (the generalization): "Every man who draws near of all your seed to the holy things, etc."