Adam Clarke's Commentary on the Bible - Genesis 7:2
Of every clean beast - So we find the distinction between clean and unclean animals existed long before the Mosaic law. This distinction seems to have been originally designed to mark those animals which were proper for sacrifice and food, from those that were not. See Leviticus 11. read more
Adam Clarke's Commentary on the Bible - Genesis 7:1
Thee have I seen righteous - See the note on Genesis 6:8 ; read more