Moses
Genesis 7:17ESV·traditional attribution

The flood continued forty days on the earth. The waters increased and bore up the ark, and it rose high above the earth.

John Calvin Reformed @genevareformer

17. And the flood was forty days , etc . Moses copiously insists upon this fact, in order to show that the whole world was immersed in the waters. Moreover, it is to be regarded as the special design of this narrations that we should not ascribe to fortune, the flood by which the world perished; how ever customary it may be for men to...

Matthew Henry Presbyterian @wholebiblehenry

We are here told, I. How long the flood was increasing - forty days, Gen 7:17. The profane world, who believed not that it would come, probably when it came flattered themselves with hopes that it would soon abate and never come to extremity; but still it increased, it prevailed. Note, 1. When God judges he will overcome.

Commenting on Genesis 7:17-20

John Gill Reformed Baptist @doctorgill

And the waters prevailed exceedingly on the earth,.... Yet more and more, so that the people without the ark were obliged to remove, not only from the lower to the higher rooms in their houses, and to the tops of them, but to the highest trees; and when these were bore down, to the highest hills and mountains; and to those it was in vain...