Hebrews 11:17-19

By faith Abraham, when he was tested [that is, as the testing of his faith was still in progress], offered up Isaac, and he who had received the promises [of God] was ready to sacrifice his only son [of promise]; [Gen 22:1-10] to whom it was said, “THROUGH ISAAC YOUR DESCENDANTS SHALL BE CALLED.” [Gen 21:12] For he considered [it reasonable to believe] that God was able to raise Isaac even from among the dead. [Indeed, in the sense that he was prepared to sacrifice Isaac in obedience to God] Abraham did receive him back [from the dead] figuratively speaking.