By faith Abraham, when he was tested, offered up Isaac, and he who had received the promises offered up his only begotten son,
Hebrews 11:17
Surrounding context
11:16 But now they desire a better, that is, a heavenly country. Therefore God is not ashamed to be called their God, for He has prepared a city for them.
11:17 By faith Abraham, when he was tested, offered up Isaac, and he who had received the promises offered up his only begotten son,
11:18 of whom it was said, "In Isaac your seed shall be called,"