Here we have the effects and evidences of the ebbing of the waters. 1. The ark rested. This was some satisfaction to Noah, to feel the house he was in upon firm ground, and no longer movable. It rested upon a mountain, whither it was directed, not by Noah's prudence (he did not steer it), but by the wise and gracious providence of God, that it might rest the sooner. Note, God has times and places of rest for his people after their tossings; and many a time he provides for their seasonable and comfortable settlement without their own contrivance and quite beyond their own foresight. The ark of the church, though sometimes tossed with tempests, and not comforted (Isa 54:11), yet has its rests, Act 9:31. 2. The tops of the mountains were seen, like little islands, appearing above the water. We must suppose that they were seen by Noah and his sons; for there were none besides to see them. It is probable that they had looked through the window of the ark every day, like the longing mariners, after a tedious voyage, to see if they could discover land, or as the prophet's servant (Kg1 18:43, Kg1 18:44), and at length they spy ground, and enter the day of the discovery in their journal. They felt ground above forty days before they saw it, according to Dr. Lightfoot's computation, whence he infers that, if the waters decreased proportionably, the ark drew eleven cubits in water.

The mountains of Ararat - That Ararat was a mountain of Armenia is almost universally agreed. What is commonly thought to be the Ararat of the Scriptures, has been visited by many travelers, and on it there are several monasteries. For a long time the world has been amused with reports that the remains of the ark were still visible there; but Mr. Tournefort, a famous French naturalist, who was on the spot, assures us that nothing of the kind is there to be seen. As there is a great chain of mountains which are called by this name, it is impossible to determine on what part of them the ark rested; but the highest part, called by some the finger mountain, has been fixed on as the most likely place. These things we must leave, and they are certainly of very little consequence.
From the circumstance of the resting of the ark on the 17th of the seventh month, Dr. Lightfoot draws this curious conclusion: That the ark drew exactly eleven cubits of water. On the first day of the month Ab the mountain tops were first seen, and then the waters had fallen fifteen cubits; for so high had they prevailed above the tops of the mountains. This decrease in the waters took up sixty days, namely, from the first of Sivan; so that they appear to have abated in the proportion of one cubit in four days. On the 16th of Sivan they had abated but four cubits; and yet on the next day the ark rested on one of the hills, when the waters must have been as yet eleven cubits above it. Thus it appears that the ark drew eleven cubits of water.

And the waters decreased continually until the tenth month,.... That is, from the seventeenth of the seventh month, to the first of the tenth month, a space of two months and thirteen days, and being summer time, through the heat of the sun, they decreased apace:

in the tenth month, on the first day of the month, were the tops of the mountains seen; not the tenth month of the flood, but of the year; the month Tammuz, as the Targum of Jonathan, and answers to part of June, and part of July; and the first day of this month, according to Bishop Usher (h), was Sunday the nineteenth of July: but according to Jarchi, whom Dr. Lightfoot (i) follows, this was the month Ab, which answers to July and August, the tenth from Marchesvan, when the rain began.

(h) Ut supra. (Annales Vet. Test. p. 4.) (i) Ut supra. (Works, vol 1. p. 6.)

And the waters decreased continually--The decrease of the waters was for wise reasons exceedingly slow and gradual--the period of their return being nearly twice as long as that of their rise.