It is God who arms me with strength and makes my way clear.
David came to the throne through almost insurmountable trials, and foreign enemies harassed him even into old age. Rather than boast of his own victories, he exalts God as the true author of them, showing that his reign prefigures Christ's kingdom, one that will triumph over all resistance by the Father's incomprehensible power.
AI summary
Commenting on Psalm 18:1-50
Some repetitions are not vain repetitions. Second thoughts upon God's mercy should be and often are the best. Like wines on the lees our gratitude grows stronger and sweeter as we meditate upon divine goodness. The verses which we have now to consider are the ripe fruit of a thankful spirit; they are apples of gold as to matter, and they are placed in baskets...
Commenting on Psalm 18:29
Surveying all the armour in which he fought and conquered, the joyful victor praises the Lord for every part of the panoply. The girdle of his loins earns the first stanza: "It is God that girdeth me with strength, and maketh my way perfect." Girt about the loins with power from heaven, the warrior was filled with vigour, far above all created might; and, whereas...