Genesis 17:17, 24-27

Abraham fell flat on his face. And then he laughed, thinking, “Can a hundred-year-old man father a son? And can Sarah, at ninety years, have a baby?”

Abraham was ninety-nine years old when he was circumcised. His son Ishmael was thirteen years old when he was circumcised. Abraham and Ishmael were circumcised the same day together with all the servants of his household, those born there and those purchased from outsiders—all were circumcised with him. * * *