Expositor's Bible Commentary Commentary Hebrews 11:18

"even he to whom it was said, In Isaac shall thy seed be called:" — Hebrews 11:18 (ASV)

The writer returns from the patriarchs in general (vv.13–16) to Abraham in particular. He now brings out something of the significance of the greatest trial that this great man had to endure: the sacrifice of his son Isaac. We are apt to see this as a conflict between Abraham’s love for his son and his duty to God. But for the author the problem was Abraham’s difficulty in reconciling the different revelations made to him. God had promised him a numerous posterity through Isaac; yet now he called on him to offer Isaac as a sacrifice. How, then, could the promise be fulfilled? Though he did not understand, Abraham knew how to obey. His faith told him that God would work out his purpose, even if he himself could not see how that could be. So he “offered Isaac as a sacrifice.” That is, in will and purpose he did offer his son. He held nothing back. At the same time, however, God did not require him to slay his “one and only” (GK 3666) son. While it is true that Abraham had other sons (Genesis 25:1–2, 5–6), he had no other born in the way Isaac was and bearing the kind of promises that were made about Isaac. Abraham’s faith is highlighted here. He was not passive; he took the responsibility of being the man through whom God would work out his promise. Yet he was ready to offer the required sacrifice. His dilemma is brought out with the quotation of God’s promise from Ge 21:12—a promise that was to be fulfilled in Isaac alone.