Genesis 22:9-12

9When they came to the place God had told him about, Abraham built the altar there and arranged the wood on it. Next he tied up his son Isaac and placed him on the altar on top of the wood.

10Then Abraham reached out his hand, took the knife, and prepared to slaughter his son.

11But the Lord’s angel called to him from heaven, “Abraham! Abraham!” “Here I am!” he answered.

12“Do not harm the boy!” the angel said. “Do not do anything to him, for now I know that you fear God because you did not withhold your son, your only son, from me.”