two. For preservation of species. In contrast with the "seven" (Genesis 7:2) clean animals, which were for sacrifice. Hence here it is Elohim (verses: Genesis 6:13; Genesis 6:22; Genesis 6:9) as the Creator; while in Genesis 7: it is Jehovah in His covenantrelation. See App-4.
Related Commentaries of Genesis 6:19
Genesis 6:19
19 And of every living thing of all flesh, two of every sort shalt thou bring into the ark, to keep them alive with thee; they shall be male and female.