Then Abraham fell upon his face, and laughed, and said in his heart, Shall a child be born unto him that is a hundred years old? and shall Sarah, that is ninety years old, bear?
Read Chapter 17
Ambrose of Milan
One should consider the fact that Abraham was uncircumcised when God called him, and he was still uncircumcised when he was promised a legitimate son as heir. You are hereby invited to believe that he is not only the father of the Jews, as they claim, but the progenitor, through faith, of all believers. Sarah also, before the circumcision of her husband and by the addition of one letter to her name, receives the blessing of no small gift, so that she might have the primacy of virtue and of grace. God promises that from her nations and kings of peoples will come, so that in her might be established the type not of the synagogue but of the church. The fact that Abraham laughed when he had been promised a son through her was an expression not of unbelief but of joy. Indeed, he “fell on his face”—in worship, which means he believed. And he added, “Shall a child be born to a man who is a hundred years old? Shall Sarah, who is ninety years old, bear a child?” And he said, “O that Ishmael mig...
: He was not laughing because he did not believe, as some might imagine, but rejoicing because he did. “He laughed” is sometimes put in place of “he rejoiced,” as it is also in the Gospels. And for this reason, he also “fell on his face” and marveled in his heart.
Now Abraham was not guilty of any doubt by his laughter, for he showed his love toward Ishmael in what he said. He had clung to this hope for twentyfive years. Abraham had manifested his faith in every vision that had come to him. However great his contest with barrenness became, he manifested the victory of his faith. But when old age was added to the barrenness, he laughed in his heart. That his Lord would do these two things for him was a marvel to him. ...