Genesis 7:3

Of fowls also of the air by sevens, the male and his female ,.... That is, of such as were clean; seven couple of these were to be brought into the ark, for the like use as of the clean beasts, and those under the law; and so at this time, and here meant were turtledoves, and young pigeons that were for sacrifice; and the rest were for food: and the design of bringing both into the ark was:

to keep seed alive upon the face of all the earth ; that the species of creatures might be continued, both of beasts and birds, clean and unclean.