Genesis 7:19-20

7:19 The waters completely inundated ¹  the earth so that even ²  all the high mountains under the entire sky were covered. 7:20 The waters rose more than twenty feet ³  above the mountains. ⁴ 

[7:19]  ¹ tn Heb “and the waters were great exceedingly, exceedingly.” The repetition emphasizes the depth of the waters.

[7:19]  ² tn Heb “and.”

[7:20]  ³ tn Heb “rose fifteen cubits.” Since a cubit is considered by most authorities to be about eighteen inches, this would make the depth 22.5 feet. This figure might give the modern reader a false impression of exactness, however, so in the translation the phrase “fifteen cubits” has been rendered “more than twenty feet.”

[7:20]  ⁴ tn Heb “the waters prevailed fifteen cubits upward and they covered the mountains.” Obviously, a flood of twenty feet did not cover the mountains; the statement must mean the flood rose about twenty feet above the highest mountain.