Augustine of Hippo

..."Hear ye these things, all ye nations" (ver. 1). Not then you only who are here. For of what power is our voice so to cry out, as that all nations may hear? For Our Lord Jesus Christ hath proclaimed it through the Apostles, hath proclaimed it in so many tongues that He sent; and we see this Psalm, which before was only repeated in one nation, in the Synagogue of the Jews, now repeated throughout the whole world, throughout all Churches; and that fulfilled which is here spoken of, "Hear ye these words, all ye nations." ...Of whom …

On the Psalms, Psalm 49 ↗

Ambrose of Milan

In the very beginning of this psalm we hear the voice of the Lord of salvation inviting the Gentiles into his church. He calls on them to renounce error, to follow truth, to fulfill the duties of love and adoration. The hearts of these people were infected by the Serpent's venom, passed down from generation to generation, and their inclination was toward sin. So long as they despair of pardon, they cannot be called back. …

Commentaries on the Twelve Davidic Psalms, On Psalm 49 ↗

Thomas Aquinas

Above, the Psalmist invited the nations to joy and thanksgiving for the benefits given to the people of God; here, however, he admonishes them to trust in God. And concerning this he does two things. First, he arouses attention. Second, he pursues his purpose. The title is not new. According to the title, however, a person is rendered attentive in two ways. In one way someone is said to be rendered attentive on the part of the hearers; in another way on the part of the things to be said, when he promises to say certain great things. …

Exposition on the Psalms of David ↗