Midrash su Levitico 7:13

4) We have learned of terumah that it is one of ten, but I still do not know from how much (flour) he takes each loaf. We derive it by deduction. It is written here (Vayikra 7:13) ("With cakes of) leavened bread," and, elsewhere, in respect to the two loaves, (Vayikra 23:17) "leavened." Just as there, an issaron (of flour) for one loaf; here, too, an issaron for one loaf.

8) Whence is it derived that the loaves of the thank-offering (Vayikra 7:13) may be brought from the tithe? From (the redundant) "which he shall offer (to the L–rd" [Vayikra 7:11]). Just as the peace-offerings may be brought from the tithe, so the loaves may be brought from the tithe.

9) We learn for "chametz" that it is ten esronoth. Whence do we learn the same for "matzah"? From (Vayikra 7:13) "With cakes of leavened (chametz) bread" — Against chametz bring matzah. Just as chametz, ten esronim; so matzah, ten esronim. I might think that the ten esronim should be only of one kind (i.e., either challoth or wafers or revuchah; it is, therefore, written (Vayikra 7:12): "Then he shall offer with the sacrifice of thanksgiving, unleavened cakes mixed with oil, and unleavened wafers spread with oil, and cakes of soaked fine flour mixed with oil," and (Vayikra 7:14): "And he shall offer of it, one of each offering, a gift-offering to the L–rd," so that we are left with three and a third esronim for each kind, and three challoth for an issaron, so that the thanksgiving challoth are found to be forty. He takes one of each kind — four challoth — and gives it to the Cohein. (Vayikra 7:14): "To the Cohein who sprinkles the blood of the peace-offerings, to him shall it be," and the rest is eaten by the owners.