Thy God hath commanded thy strength,.... Which is either an apostrophe or an address to the Messiah, as in Psa 45:7; declaring, that as his God and Father had purposed and promised to send forth, so he had sent forth, the rod of his strength out of Zion, Psa 110:1; that is, his Gospel, both into the several cities of Judea, and into the Gentile world, where it was the power of God unto salvation, both to Jew and Gentile: or else these words are spoken to the churches and congregations, in whom the Lord's name was to be blessed; or to the princes, rulers, and governors of them before mentioned, showing that the Lord has made good his promise to them, that as their day was their strength should be; and it was owing to their being strengthened by him that they walked up and down in his name, doing his work, and preaching his Gospel, both to Jews and Gentiles: to which they reply by petition, strengthen, O God, that which thou hast wrought for us; which, if understood of the apostles, princes, and rulers, refers to the work of preaching the Gospel, and the success of it, desiring it might be more and more confirmed; and to the settlement of Christianity in the Pagan world, and also to the work of the reformation from Popery in later times; compare with this Rev 3:2; if of the churches, and the members thereof, it may respect the carrying on and finishing the work of grace in them. It is rendered "in us" by the Septuagint and others; see Isa 26:12; for this work sometimes seems to be very low and weak, and needs strengthening, and it is God only that can do it, and he will do it, Pe1 5:10; and this shows that the grace of God is not only necessary at first conversion, but to be continued for the performing of the work of grace until the day of Christ.