Augustine of Hippo

"He has founded it above the seas." He has most firmly established it above all the waves of this world, that they should be subdued by it, and should not hurt it. "And has prepared it above the rivers" [Psalm 24:2]. The rivers flow into the sea, and men of lust lapse into the world: these also the Church, which, when worldly lusts have been conquered by the grace of God, has been prepared by love for the reception of immortality, subdues.

Exposition on Psalm 24 ↗

Thomas Aquinas

Next he gives the reason for the aforesaid, because namely "he founded it upon the seas"; as if to say: that belongs to the craftsman which the craftsman himself makes. But God made the earth and the things that are on the earth. Therefore the earth and its fullness are his. But some say that God's providence does not extend to earthly things. But against this is the sign of great providence in the arrangement of the waters in relation to the earth, because the lighter elements ought to be above the heavier ones. …

Exposition on the Psalms of David ↗

Bonaventure

The Psalm says: "Upon the seas he founded it"; and elsewhere: "Who founded the earth upon its own stability." Some mocked David because he said that God founded the earth upon the waters. The earth, since it is dry, unless there were moisture penetrating it, would be reduced to dust; and just as the human body receives moisture through its veins, so it is necessary that fresh waters come from the sea and hold the earth together. He says that he founded the earth upon the waters on account of the mystery. …

Collationes de Septem Donis, Collation 4 ↗