Psa 21:1-13. The pious are led by the Psalmist to celebrate God’s favor to the king in the already conferred and in prospective victories. The doxology added may relate to both Psalms; the preceding of petition, chiefly this of thanksgiving, ascribing honor to God for His display of grace and power to His Church in all ages, not only under David, but also under his last greatest successor, “the King of the Jews.”
thy strength ... thy salvation - as supplied by Thee.