Midrash sur La Genèse 1:25

After the Holy One, blessed be He, created his world, it is written: God blessed the seventh day (Gen. 2:3) After He created the beasts and the birds it is written: He blessed them (ibid., v. 28), and with reference to the creation of man it is written: He blessed them and called their name Adam (ibid. 5:2). He likewise blessed the reptiles and food.

(Gen. 6:9:) THESE ARE THE GENERATIONS OF NOAH; [NOAH WAS A RIGHTEOUS MAN]. Why the twofold NOAH NOAH? Because his children were righteous like him. R. Aha bar Ze'era said: Would you say the children of Noah were righteous, seeing that the generation of the flood was born in wickedness! Even as one would go unto a wife who was not his own, so would the cattle go to another species which was not their own. And where is it shown that the cattle were commanded not to go unto a species which was not their own? Where it is stated (in Gen. 1:25): AND GOD MADE THE BEAST OF THE EARTH AFTER ITS SPECIES, < THE CATTLE AFTER THEIR SPECIES >…. The Holy One SAID: You are permitted to be joined with your own species, but with another species it is forbidden.¹⁹Tanh., Gen. 2:5. The cattle, beasts, and fowl who entered the ark, however, were righteous in that they had been joined, not with another species, but only with their own. R. Pinhas bar Hiyya the Priest said: For thus it is written (in Gen. 8:19): THEY WENT FORTH FROM THE ARK ACCORDING TO THEIR FAMILIES. Did the cattle actually have families as it states: ACCORDING TO THEIR FAMILIES! < These words mean > simply that only those which were joined with their own species were worthy of entering the ark.

R. Ahava the son of R. Ze’era said: Even Noah’s sons, the animals, the beasts, the birds, and the creeping things that accompanied him into the ark were righteous. At the time of the generation of the flood, all flesh had corrupted their way upon the earth (Gen. 6:12), as it is stated in Scripture concerning them. The domesticated animals copulated with the beasts, the beasts with the animals, they with men, and the men with them. Therefore, it is stated: Behold, I will destroy them with the earth (ibid., v. 13). How do we know that at the very hour that they were created, the animals, the beasts, the birds, and the creeping things were commanded not to copulate with any species other than their own? It is written: And God made the beast of the earth after its kind (Gen. 1:25). The Holy One, blessed be He, told them: Each shall cleave to its own and is forbidden to go to another.