George Haydock's Catholic Commentary
Psalms 17:50
Nations. St. Paul (Romans xv. 9.) adduces this to prove the vocation of the Gentiles. (Calmet) --- We cannot doubt but the great things announced in the psalm pertain to Christ. (Berthier) --- We see the completion of this prophecy, as there is no Christian nation which does not use the psalms of David to praise God. (Theodoret, &c.) --- This practice is very common (Pref.; Worthington) in all places here either Jews or Christians are found.