Augustine of Hippo

And again he says, "both all you earthborn, and sons of men" [Psalm 49:2]. The expression "earthborn" refers to sinners; the expression "sons of men" to the faithful and righteous. You see then that this distinction is observed. Who are the "earthborn"? The children of the earth. Who are the children of the earth? They who desire earthly inheritances. Who are the "sons of men"? They who appertain to the Son of Man. …

Exposition on Psalm 49 ↗

Ambrose of Milan

Both rich and poor together are called to a single vocation and invited to a certain humility and equality. The rich are not to turn up their noses at the poor, and the poor are not to be jealous of the rich. One grace joins both together. The Lord, though he was rich, became poor, so as to be Savior of poor and rich alike.

Commentaries on the Twelve Davidic Psalms, On Psalm 49 ↗

Thomas Aquinas

He sets forth the third when he says, "all you who are earth-born," that is, the ignoble, "and sons of men," that is, the noble. Jerome has, "both sons of Adam and sons of individuals," because some have nothing distinguished from their parents. Mystically, the "earth-born" are called sinners, who cling to the earth through affection; hence they are compared to the serpent. Is. …

Exposition on the Psalms of David ↗