Genesis 22:9-12

9When they came to the place of which God had told him, Abraham built an altar there and arranged the wood, and bound Isaac his son and placed him on the altar, on top of the wood.

10Abraham reached out his hand and took the knife to kill his son.

11But the Angel of the Lord called to him from heaven and said, “Abraham, Abraham!” He answered, “Here I am.”

12The Lord said, “Do not reach out [with the knife in] your hand against the boy, and do nothing to [harm] him; for now I know that you fear God [with reverence and profound respect], since you have not withheld from Me your son, your only son [of promise].”