New Defender's Study Bible Notes
3:20 days of Noah. It was “in the days of Noah” when this flagrant disobedience of the angels took place, resulting in this severe punishment.
3:20 ark was a preparing. During the “days while the ark was a preparing,” Noah preached righteousness to the demon-controlled people of his generation (note II Peter 2:5), and God was “longsuffering.” But none heeded, and only eight were spared in the ark when the Flood came.
3:20 saved by water. These eight (Noah, his three sons, and the four wives) were “saved by water” (this could also be translated “through water”) in the sense that they were saved from the deadly moral and spiritual pollution that had engulfed the antediluvian world after the demonic invasion. The waters bore up their ark of safety, even as these same waters destroyed the old world and their old lives.