Charles Ellicott Commentary Genesis 7:4

"For yet seven days, and I will cause it to rain upon the earth forty days and forty nights; and every living thing that I have made will I destroy from off the face of the ground." — Genesis 7:4 (ASV)

Forty days. —Henceforth, forty became the sacred number of trial and patience. Besides the obvious places in the Old Testament, it was also the duration of our Lord’s fast in the wilderness and His sojourn on earth after the Resurrection.

Every living substance. —The word “living” is found neither in the Hebrew nor in the ancient versions, and it limits the sense unnecessarily. The word is rare, being found only three times, namely: here, in Genesis 7:23, and in Deuteronomy 11:6. It means whatever stands erect. Thus God “destroys”—Hebrew, blots out ()—not only man and beast, but the whole existing state of things—“from the face of the earth”—Hebrew, the adâmâh, the cultivated and inhabited ground. This section assigns a much more limited extent to the flood. It does not include reptiles (or rather, small animals) among those saved in the ark, and it confines the overflow of the waters to the inhabited region.