Genesis 22:9-12

⁹And they came to the place which God had shown him, where he built an altar, and laid the wood in order upon it: and when he had bound Isaac his son, he laid him on the altar upon the pile of wood.

¹⁰And he put forth his hand and took the sword, to sacrifice his son.

¹¹And behold an angel of the Lord from heaven called to him, saying: Abraham, Abraham. And he answered: Here I am.

¹²And he said to him: Lay not thy hand upon the boy, neither do thou any thing to him: now I know that thou fearest God, and hast not spared thy only begotten son for my sake.e