Genesis 22:9-12

9When they reached the place God had told him about, Abraham built an altar there and arranged the wood on it. He bound his son Isaac and laid him on the altar, on top of the wood. 10Then he reached out his hand and took the knife to slay his son. 11But the angel of the Lord called out to him from heaven, “Abraham! Abraham!” “Here I am,” he replied. 12“Do not lay a hand on the boy,” he said. “Do not do anything to him. Now I know that you fear God, because you have not withheld from me your son, your only son.”