Genesis 22:12-13

12The angel said, ‘Do not hurt the boy! Do not do anything to him. Now I know that you respect God and you obey him. Isaac is your only son and you agreed to offer him to me as a sacrifice. You did not try to keep him safe.’

13Just then, Abraham looked round and he saw a male sheep behind him. Its horns were caught in some bushes. So he went and he took hold of the sheep. Abraham killed the sheep on the altar as a burnt offering to God. In that way, he killed the sheep as a sacrifice, instead of his son.