The waters prevail, and all flesh dies (Genesis 7:17–24)

Says The waters lift the ark (7:17). “Finally, the waters completely prevailed upon the earth, so that all the high mountains under all the heavens were covered” (7:19, BSB). The Hebrew of 7:20 is חֲמֵשׁ עֶשְׂרֵה אַמָּה מִלְמַעְלָה גָּבְרוּ הַמָּיִם, fifteen cubits upward the waters prevailed, וַיְכֻסּוּ הֶהָרִים, and the mountains were covered. The BSB has the waters covering the mountaintops to a depth of fifteen cubits. All flesh on the dry ground dies; only Noah and those with him are left (7:21–24). See the language notes.

Implies The verb גבר is one of strength, not height: the waters prevail; their rising is told by other verbs in 7:17.

Uncertain What the fifteen cubits measure, and how far the flood reached, are open. (1) The depth over the highest mountains: ground, the clause stands between the two coverings of the mountains; objection, it does not name them as its base. (2) A depth tied to the ark, half its thirty cubits (6:15): ground, the water needed to float clear; objection, 7:20 does not name the ark. Neither settles the extent. (1) A flood of the whole earth: ground, all flesh, all the high mountains under all the heavens. Objection: all and the earth can name a land and its people. (2) A flood of a region: ground, that narrower use. Objection: the chapter repeats its widest terms. The New Testament use does not settle the extent. The Babylonian accounts are in the historical note; no dependence is claimed.