The Greek term behind the word “waited” is an intensified form of the normal word for “to wait.” This intensified form conveys the notion of “eagerly waiting” (Hebrews 9:28). That Peter uses this intensified form here indicates a measure of impatience within God about when the flood could begin. Peter suggests an impatient long-sufferance on God’s part.
20 because they formerly did not obey, when God’s patience waited in the days of Noah, while the ark was being prepared, in which a few, that is, eight persons, were brought safely through water.