2 Peter 3:6

It seems, however, strange that he says that the world perished through the deluge, when he had before mentioned the heaven and the earth. To this I answer, that the heaven was then also submerged, that is, the region of the air, which stood open between the two waters. For the division or separation, mentioned by Moses, was then confounded. (Genesis 1:6;) and the word heaven is often taken in this sense. if any wishes for more on this subject, let him read Augustine on the City of God. Lib. 20. (178)

The δι ᾿ ὧν at the beginning of the sixth verse, refers, according to Beza, Whitby, and others, to the heavens and the earth in the preceding verse, the deluge being occasioned by “the windows of heaven being opened,” and “the fountains of the great deep being broken up.” (Genesis 7:11.) “By which (or by the means of which) the world at that time, being overflowed with water, was destroyed.”

The objection to this view is, as justly stated by Macknight, that the correspondence between this verse and the following is thereby lost: the reservation of the world to be destroyed by fire is expressly ascribed, in verse seventh, to God’s word; and to the same ought the destruction of the old world to be ascribed. This is doubtless the meaning required by the passage, but “which” being in the plural, creates a difficulty, and there is no different reading. Macknight solves the difficulty by saying that the plural “which” or whom, refers to “word,” meaning Christ, and “God,” as in the first verse of this chapter, “in both which,” a reference is made to what is implied in “the second Epistle,” that is, the first. He supposes that there is here the same anomalous mode of speaking. But the conjecture which has been made is not improbable, that it is a typographical mistake, ὧν being put for οὗ or for ὃν. Then the meaning would be evident; and the two parts would correspond the one with the other:

5. “For of this they are wilfully ignorant, that the heavens existed of old and the earth (which subsisted from water and in water,) by
6. the word of God; by which the world at that time, being over-
7. flowed with water, was destroyed. But the present heavens and the earth are by His word reserved, being kept for fire to the day of judgment and of the perdition of ungodly men.”

By “word” here is meant command, or power, or the fiat by which the world was created; and by the same it was destroyed, and by the same it will be finally destroyed. Instead of αὐτῶ “the same” Griesbach has introduced into his text αὐτοῦ, “His.” — Ed