Jamieson, Fausset and Brown on Psalms 45:12

12. daughter of Tyre--(Psa 9:14); denotes the people. Tyre, celebrated for its great wealth, is selected to represent the richest nations, an idea confirmed by the next clause. These gifts are brought as means to conciliate the royal parties, representing the admitted subjection of the offerers. This well sets forth the exalted position of the Church and her head, whose moral qualities receive the homage of the world. The contribution of material wealth to sustain the institutions of the Church may be included (compare "riches of the Gentiles," Psa 72:10; Is 60:5-10).