Fifty and a hundred days. - These, and the forty days of rain, make one hundred and ninety days: about six lunar months and thirteen days. If to this we add the month and seventeen days before the commencement of the rain, we have eight months completed, and are therefore brought to the first day of the ninth month. The waters may be said to prevail as long as the ark had its full draught of water. It is probable they were still rising during the first half of the hundred and fifty days, and then gradually sinking during the other half.

And the waters prevailed upon the earth a hundred and fifty days - The breaking up of the fountains of the great deep, and the raining forty days and nights, had raised the waters fifteen cubits above the highest mountains; after which forty days it appears to have continued at this height for one hundred and fifty days more. "So," says Dr. Lightfoot, "these two sums are to be reckoned distinct, and not the forty days included in the one hundred and fifty; so that when the one hundred and fifty days were ended, there were six months and ten days of the flood past." For an improvement of this awful judgment, see the conclusion of the following chapter, Genesis 8:22 (note).

And the waters prevailed upon the earth one hundred and fifty days. Which is to be reckoned not from the end of the forty days' rain, but from the beginning of the flood; for from the seventeenth day of the second month, when the fountains of the deep were broken up, and the windows of heaven were opened, unto the seventeenth day of the seventh month, when the ark rested on the mountains of Ararat, and the waters decreased, were just five months, or one hundred and fifty days; until which time the waters increased yet more and more, even after the forty days' rain; so that it seems there was a continual rain afterwards, as Aben Ezra observes, though not so vehement; or otherwise it is not so easy to account for the increase of the waters.

an hundred and fifty days--a period of five months. Though long before that every living creature must have been drowned, such a lengthened continuance of the flood was designed to manifest God's stern displeasure at sin and sinners. Think of Noah during such a crisis. We learn (Ezekiel 14:14) that he was a man who lived and breathed habitually in an atmosphere of devotion; and having in the exercise of this high-toned faith made God his refuge, he did not fear "though the waters roared and were troubled; though the mountains shook with the swelling thereof" [Psalm 46:3].