“From every pure animal, you shall take to you seven pairs, a male and his mate, and of the animals that are not pure, two, a male and his mate” (Genesis 7:2). “From every pure animal…” – Rabbi Yudan in the name of Rabbi Yoḥanan, Rabbi Berekhya in the name of Rabbi Eliezer, and Rabbi Yaakov of Kefar Ḥanin in the name of Rabbi Yehoshua ben Levi: We find that the Holy One blessed be He went out of His way to add two or three words in the Torah so as to avoid uttering an expression of impurity.
That is what is written: “From every pure animal, you shall take to you seven pairs, a male and his mate,”; “and of the unclean animals” is not written here, but rather, “and of the animals that are not pure.” Rabbi Yudan ben Rabbi Menashe said: Also, when He came to tell them [the people of Israel] the signs of an unclean animal, He began only with the signs of the pure animal:15The Torah mentions four animals that possess one of the two signs of pureness, but are missing the second.
In each case the Torah first states the sign that the animal does possess, and afterwards the sign that is lacking. “The camel, because its hoof is not split” is not written [first] here, but rather, “because it brings up the cud” (Leviticus 11:4). “And the hyrax, because its hoof is not split” is not written [first] here, but rather, “because it brings up the cud” (Leviticus 11:5). “And the pig, because it does not bring up its cud” is not written [first] here, but rather, “because its hoof is split” (Leviticus 11:7).
“Also from the birds of the heavens, seven each, male and female, to sustain offspring on the face of all the earth” (Genesis 7:3). “Also from the bird of the heavens, seven each” – if you say that this means [just seven birds] from each species, would there not be one [bird] that remains without a mate? It means, rather, seven males and seven females. It is not that I [God] need them, but rather, it is “to sustain offspring on the face of all the earth.”