8 Do we not read throughout the Scriptures that Christ is the King? He it is that shall come out of Jacob to rule, who has been set by the Father as king over Sion, his holy mount, and shall have the Gentiles for his inheritance, and the utmost parts of the earth for his possession. In the nuptial hymn, where the future King of Israel is hailed as a most rich and powerful monarch, we read: "Thy throne, O God, is for ever and ever; the scepter of thy kingdom is a scepter of righteousness." There are many similar passages, but there is one in which Christ is even more clearly indicated. Here it is foretold that his kingdom will have no limits, and will be enriched with justice and peace: "in his days shall justice spring up, and abundance of peace...And he shall rule from sea to sea, and from the river unto the ends of the earth."
Source: Quas Primas (Vatican.va)