Genesis 7:1-3

And the LORD said unto Noah, Come thou and all thy house into the ark; for thee have I seen righteous before me in this generation.

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.

Of fowls also of the air by sevens, the male and the female; to keep seed alive upon the face of all the earth.