Hebrews 11:19

Verse 19. Accounting that God was able to raise him up, even from the dead. And that he would do it; for so Abraham evidently believed, and this idea is plainly implied in the whole narrative. There was no other way in which the promise could be fulfilled; and Abraham reasoned justly in the case. He had received the promise of a numerous posterity, he had been told expressly that it was to be through this favourite child, he was now commanded to put him to death as a sacrifice, and he prepared to do it. To fulfil these promises, therefore, there was no other way possible but for him to be raised up from the dead, and Abraham fully believed that it would be done.