Of the descendants of Judah, registered by name and lineage according to their clans and ancestral houses, every male of twenty years or more, everyone fit for military service:
Then he gave him the covenant of circumcision, and so he became the father of Isaac, and circumcised him on the eighth day, as Isaac did Jacob, and Jacob the twelve patriarchs.
By faith he received power to generate, even though he was past the normal age—and Sarah herself was sterile—for he thought that the one who had made the promise was trustworthy.