Genesis 7:2

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. Here the account is more specific, distinguishing between clean and unclean animals. Cf Leviticus 11; Deuteronomy 14. of clean animals a total of seven of each kind were to be taken into the ark, probably three pairs and a fourth male intended for a sacrificial animal; but with regard to the unclean animals the arrangement by pairs was observed.