Hebrews 11:8-11 ESV
By faith Abraham obeyed when he was called to go out to a place that he was to receive as an inheritance. And he went out, not knowing where he was going. By faith he went to live in the land of promise, as in a foreign land, living in tents with Isaac and Jacob, heirs with him of the same promise. For he was looking forward to the city that has foundations, whose designer and builder is God. By faith Sarah herself received power to conceive, even when she was past the age, since she considered him faithful who had promised.