Charles H. Spurgeon on Psalms 61:6

Thou wilt prolong the king's life; or, better, "days to the days of the King thou wilt add." Death threatened, but God preserved his beloved. David, considering his many perils, enjoyed a long and prosperous reign. And his years as many generations. He lived to see generation after generation personally; in his descendants he lived as king through a very long period; his dynasty continued for many generations; and in Christ Jesus, his seed and son, spiritually David reigns on evermore. Thus he who began at the foot of the rock, half drowned, and almost dead, is here led to the summit, and sings as a priest abiding in the tabernacle, a king ruling with God for ever, and a prophet foretelling good things to come. (Ps 61:7.) See the uplifting power of faith and prayer. None so low but they may yet be set on high.