Genesis 11:30

But Sarai was barren; she had no child.
] Aben Ezra observes, there are some that say that Abraham was impotent, and not Sarai barren; the very reverse of the Scriptures; but as he rightly adds, his son Ishmael and his sons by Keturah show the contrary, see ( Genesis 15:2 ) ( 16:1 ) .