Why Did God Swear an Oath to Abraham? (Genesis 22:15–24)

The ram was still burning when the voice came again. "And the angel of the LORD called to Abraham from heaven a second time" (Genesis 22:15).

Abraham had already heard God on this journey, first the command three days earlier and then his own name, called twice while the knife was in his hand. He had named the mountain. God had more to say.

What did God promise Abraham in Genesis 22:15–18?

"By Myself I have sworn, declares the LORD, that because you have done this and have not withheld your only son" (Genesis 22:16). Then the promise itself: "I will surely bless you, and I will multiply your descendants like the stars in the sky and the sand on the seashore. Your descendants will possess the gates of their enemies" (Genesis 22:17).

Most of these words were old. Abraham had stood outside his tent years before and been told to count the stars (Genesis 15:5). The blessing for every nation went back to the first call in Haran (Genesis 12:3). What was new was the oath. This is the first time Genesis shows God swearing, and with no one higher to call as witness, He swore by Himself. The letter to the Hebrews puts it plainly: "since He had no one greater to swear by, He swore by Himself" (Hebrews 6:13).

God's word was already true, and Hebrews gives the reason for the oath. "So when God wanted to make the unchanging nature of His purpose very clear to the heirs of the promise, He guaranteed it with an oath" (Hebrews 6:17). The oath was for Abraham, and for everyone who would hold the same promise after him, so that we "may be strongly encouraged" (Hebrews 6:18).

What does "because you have obeyed My voice" mean?

The oath ends on Abraham's part in it: "because you have obeyed My voice" (Genesis 22:18). The Hebrew verb is shama', to hear. Hebrew uses the same word for hearing and for obeying, so to hear God's voice properly is to act on it. Abraham had heard, and walked three days on what he heard. God made Himself known to a man who listened, and Abraham came to know Him as the God who keeps His word with an oath.

How does Genesis 22:18 point to Jesus?

"And through your offspring all nations of the earth will be blessed" (Genesis 22:18). Paul noticed that the promise speaks of one offspring, a single seed, "meaning One, who is Christ" (Galatians 3:16). The blessing sworn on Moriah reaches the nations through the Son God did not withhold.

Some two thousand years after Moriah, Zechariah held his newborn son John and sang that God had remembered "the oath He swore to our father Abraham" (Luke 1:73). The Messiah was about to be born, and a priest was still singing about the oath God swore on that mountain.

Who is Rebekah in Genesis 22?

Abraham walked home to Beersheba (Genesis 22:19). Some time later a report came about his brother Nahor's family: eight sons, a list of names, and one granddaughter. "And Bethuel became the father of Rebekah" (Genesis 22:23). Abraham could not have known what that line meant. The girl who would marry Isaac was already alive in his brother's household, and God was keeping the oath before Abraham saw how.

God spoke to Abraham twice on that mountain, and the second time He confirmed what He had already said. When God says something to you and then says it again, through Scripture, a friend or a quiet moment of prayer, record both times in the Doxa app with the dates. You will want to find them both on the day the promise looks furthest away.

What has God said to you more than once?

Deeper study today in the Doxa Deeper Dive: the prayer at Sinai that quoted this oath back to God, and why the place name Beersheba means more than it seems. Read it here.