John Calvin Commentary Psalms 59:16

"But I will sing of thy strength; Yea, I will sing aloud of thy lovingkindness in the morning: For thou hast been my high tower, And a refuge in the day of my distress." — Psalms 59:16 (ASV)

But I will sing of thy power. By this, he does not mean merely that he would have an occasion to sing at some future time, but he prepares himself immediately for the act of thanksgiving; and he proceeds to acknowledge that his deliverance would be at once an illustrious effect of Divine power and conferred by mere grace.

It may be true that David escaped from the hands of his enemies at this time quietly and secretly, through the cleverness of his wife. Still, by means of this stratagem, God thwarted the preparations and forces of Saul, and may, therefore, rightly be said to have exerted His power.

We may suppose, however, that David takes this particular instance as an opportunity to look further back and consider the various Divine interventions he had experienced.