John Calvin on Genesis 22:3

3. And Abraham rose up early in the morning. This promptitude shows the greatness of Abraham’s faith. Innumerable thoughts might come into the mind of the holy man; each of which would have overwhelmed his spirit, unless he had fortified it by faith. And there is no doubt that Satan, during the darkness of the night, would heap upon him a vast mass of cares. Gradually to overcome them, by contending with them, was the part of heroical courage. But when they were overcome, then immediately to gird himself to the fulfillment of the command of God, and even to rise early in the morning to do it, was a remarkable effort. Other men, prostrated by a message so dire and terrible, would have fainted, and have lain torpid, as if deprived of life; but the first dawn of morning was scarcely early enough for Abraham’s haste. Therefore, in a few words, Moses highly extols his faith, when he declares that it surmounted, in so short a space of time, the very temptation which was attended with many labyrinths.