Genesis 22:9-13

Then they came to the place of which God had told him; and Abraham built the altar there and arranged the wood, and bound his son Isaac and laid him on the altar, on top of the wood. Abraham stretched out his hand and took the knife to slay his son. But the angel of the LORD called to him from heaven and said, “Abraham, Abraham!” And he said, “Here I am.” He said, “Do not stretch out your hand against the lad, and do nothing to him; for now I know that you fear God, since you have not withheld your son, your only son, from Me.” Then Abraham raised his eyes and looked, and behold, behind him a ram caught in the thicket by his horns; and Abraham went and took the ram and offered him up for a burnt offering in the place of his son.