Matthew Poole and continuators on Genesis 7:2

2. Of every clean Beast thou shalt take to thee by sevens , the Male and his Female: and of Beasts that are not clean, by two, the Male and his Female.

Obj. The distinction of clean and unclean Beasts was not before the Law. Answ. Some legal things were prescribed and used before the Law, as abstinence from the eating of Blood, Gen. 9. 4. and among other things, Sacrifices, as Learned men have sufficiently proved; and consequently the distinction of Beasts to be Sacrificed was then in some measure understood, which afterwards was expressed, Levit. 1. &c. Nor is this a good argument, This was not written before, therefore it was not commanded and practised before, especially concerning a time when no commands of God were written, but only delivered by tradition.

Either 1. Seven single, as most think. Or rather 2. Seven couples, as may be gathered 1. From the duplication of the word in Hebrew. If it be said, seven seven signifies only seven of every kind, then it would have been said concerning the unclean Beasts, two two, (i. e.) two of each sort: Whereas now there is an apparent difference, there it is said only by two, but here, by sevens, or seven seven, which difference of the phrase suggests a difference in the things. 2. By the following words, the Male and his Female, which being indifferently applied to the clean and unclean, plainly shews that none of them entred into the Ark single, and therefore there was no odd seventh among them, but all went in by couples, which was most convenient in all for the propagation of their kind, and in the clean for other uses also, as for Sacrifices to God, if not for the sustentation of Men in the Ark, and after they came out of it. Which gives us the reason why God would have more of the clean than of the unclean put into the Ark, because they were more serviceable both to God and Men.

Marginal references: Heb. seven seven.; Heb. the Man and his Wife.