Genesis 21:2

The plans of the LORD stand firm forever, the purposes of his heart through all generations” (Psalm 33:11). But we must be prepared to wait on God’s timing. His timing is precise, for He does things “at the very time” He has set. It is not for us to know His timing, and in fact we cannot know it—we must wait for it.

If God had told Abraham while he was in Haran that he would have to wait thirty years before holding his promised child in his arms, his heart might have failed him. So God, as an act of His gracious love, hid from Abraham the number of weary years he would be required to wait. Only as the time was approaching, with but a few months left to wait, did God reveal His promise: “At the appointed time next year . . . Sarah will have a son” (Genesis 18:14). The “appointed time” came at last, and soon the joyous laughter that filled the patriarch’s home caused the now elderly couple to forget their long and tiring wait.