John Calvin Commentary Psalms 27:14

"Wait for Jehovah: Be strong, and let thy heart take courage; Yea, wait thou for Jehovah." — Psalms 27:14 (ASV)

Wait you on Jehovah. It may be doubted whether David, having spoken of himself in the preceding verses, here addresses his words to others, exhorting them by his own example to fortitude and persevering patience. He does similarly in the conclusion of Psalm 31:19, where, after speaking about himself particularly, he makes a transition and addresses all the godly.

But since he speaks here in the singular number and uses no mark to show that he directs his words to others, it is, in my opinion, probable that he applies it to himself to further encourage his confidence in God, lest his heart should faint at any time.

As he was conscious of his weakness and knew that his faith was the great means of keeping him safe, he appropriately strengthened himself for the future. Under the word waiting, he also reminded himself of new trials and set before his own eyes the cross he must bear.

We are said to wait on God, then, when He, withdrawing His grace from us, allows us to languish under afflictions. David, therefore, having passed through one conflict, prepared himself to encounter new ones.

But since nothing is more difficult than to give God the honor of relying upon Him when He hides Himself from us or delays His assistance, David roused himself to gather strength. It is as if he had said to himself: "If fearfulness steals upon you, if temptation shakes your faith, if the feelings of the flesh rise in tumult, do not faint. Instead, strive to rise above them with an invincible resolution of mind."

From this we may learn that the children of God overcome not by sullenness but by patience, when they commit their souls quietly to God, as Isaiah says, “In quietness and in confidence shall be your strength” (Isaiah 30:15).

Since David did not feel himself equal to great and difficult efforts, he borrowed strength from God through prayer. If he had said no more than Act like a man, he would have appeared to be relying on his own free will. But as he immediately adds, by way of correction, that God would be ready to strengthen his heart, he clearly shows that when the saints strive vigorously, they fight in the strength of Another, and not in their own.

David does not, like the Papists, put his own efforts first and afterward pray for divine aid. Instead, after doing his own duty, although he knew that he was lacking strength in himself, he requests that his deficiency be supplied by the grace of the Holy Spirit.

And since he knew that this battle must continue throughout his whole life, that new conflicts would arise daily, and that the troubles of the saints are often prolonged, he again repeats what he had said about waiting on God: Wait you alone on Jehovah.