Cosmas Indicopleustes

David composed the eighth psalm with reference to Christ, speaking of his divine nature in the first verses of it, as the Lord Christ himself also testifies of it in the Gospel, when they strewed his way with branches and praised him with shouts of welcome, saying: Hosanna to the son of David! Blessed is he that cometh in the name of the Lord! …

The Christian Topography, Book 5 ↗

Augustine of Hippo

"Out of the mouth of babes and sucklings Thou hast made perfect praise, because of Thine enemies" [Psalm 8:2]. I cannot take babes and sucklings to be any other than those to whom the Apostle says, "As unto babes in Christ I have given you milk to drink, not meat." [1 Corinthians 3:1-2] Who were meant by those who went before the Lord praising Him, of whom the Lord Himself used this testimony, when He answered the Jews who bade Him rebuke them, "Have ye not read, out of the mouth of babes and sucklings Thou hast made perfect praise?" …

On the Psalms ↗

Thomas Aquinas

Then when he says "Out of the mouths," he shows that it is most manifest. And first he shows the manifestation. Second, the reason for it, at "For I shall see." That it is manifest he proves, because that is manifest which is implanted in all people, however simple they may be, as if by a kind of natural knowledge. For there is a twofold kind of people who follow the natural and right instinct, namely the simple and the wise. That the wise should know God is not a great thing; but that the simple should, that is remarkable. …

Exposition on the Psalms of David ↗