Hebrews 11:11-12, 19

By faith Sarah herself received power to conceive, even when she was past the age, since she considered him faithful who had promised. Therefore from one man, and him as good as dead, were born descendants as many as the stars of heaven and as many as the innumerable grains of sand by the seashore.

He considered that God was able even to raise him from the dead, from which, figuratively speaking, he did receive him back.