Thomas Aquinas

923. Concerning the second, he does three things. First, he gives an example: look unto the rock, namely, Abraham, because of his old age, whence you are hewn, as though violently, not according to the course of nature; and to the hole of the pit, namely, Sarah, to whom it had ceased to be after the manner of women (Gen 18:11): neither did he consider his own body, when it was already dead (Rom 4:19), in which is shown that God has power to make fertile; for I called him alone (cf. Gen 12:1): Abraham was one (Ezek 33:24).

Commentary on Isaiah ↗