Genesis 22:10-13

And Abraham stretched out his hand, and took the knife to slaughter his son. And the Angel of Jehovah called to him from the heavens, and said, Abraham, Abraham! And he said, Here am I. And he said, Stretch not out thy hand against the lad, neither do anything to him; for now I know that thou fearest God and hast not withheld thy son, thine only son, from me. And Abraham lifted up his eyes, and looked, and behold, behind was a ram caught in the thicket by its horns; and Abraham went and took the ram, and offered it up for a burnt-offering instead of his son.