Genesis 7:2

Of every clean beast The distinction is here made between the clean and the unclean animals. Categories of both kinds, according to the Levitical Law, are found in Leviticus 11 and Deuteronomy 14:3-20. In the account given by P (Genesis 6:19) no allusion is made to this distinction. According to P, the distinctions of clean and unclean were for the first time laid down in the Mosaic legislation, and could not, therefore, be recognized as existing in the primaeval or patriarchal age. According to J, the distinction existed in pre-Mosaic times, and was to be presupposed as having existed side by side with the institution of sacrifice.

seven and seven, the male and his female By this is meant seven pairs. "The male and his female," i.e. "each and his mate," îsh v'ishtô, seems to make this clear. But some consider seven clean animals, and not seven pairs of clean animals, are intended. The words "the male and his female" are different from those rendered "male and female," zâkâr un"ḳêbah, Genesis 1:27; Genesis 6:19; Genesis 7:3; Genesis 7:9; Genesis 7:16.

The reason why so many more clean animals than unclean are required is, presumably, because they would be wanted (a) for food, (b) for sacrifice, and (c) for domestic purposes.

There is no reason to assume that the J tradition of the narrative shared the opinion of the P tradition, that before the Flood man subsisted on vegetable diet (see Genesis 1:29; Genesis 6:20; Genesis 9:2-3).