And the waters returned from off the earth continually: and after the end of the hundred and fifty days the waters were abated.
I distinguish the timing carefully: rain fell for forty days while waters rose, then they held nearly steady for one hundred fifty days before subsiding. The Lord stretched this desolation across time to show plainly that the flood was no accident but His judgment, and Noah's deliverance a magnificent and lasting proof of His grace.
AI summary
God remembered Noah when mankind itself was driven into forgetfulness. The whole race was extinguished except Noah's family, so His remembering Noah was mercy's return to mankind. Even the faithful grow weary in long affliction and fear they are forgotten; Noah perhaps thought so too when the waters lingered. But God restrained His wrath and showed Himself to him at last.
AI summary
Commenting on Genesis 8:1-3
The waters returned to their proper places appointed for them, some dried up by wind and sun into the air, others soaking into the earth or flowing back to their channels. At one hundred fifty days from the flood's beginning, including the forty days of rain, the waters began to abate and recede.
AI summary