Fifteen cubits upward did the waters prevail; and the mountains were covered.
Fifteen cubits upward. Estimating the cubit at eighteen inches, then the waters were twenty-three feet above the peaks of the highest mountain, and this accurate measurement of the depth by sounding the plummet would show, that not only careful observations were made, but a faithful record was kept by Noah or some of his family. But according to Delitzsch, 'this statement, that the water rose fifteen cubits above the mountains, is probably founded upon the fact that the ark drew fifteen feet of water, and that, when the waters subsided, it rested on the mountains of Ararat, from which the conclusion would very naturally be drawn as to the greatest height attained' (see the note at Genesis 8:4).