Rashi on Genesis 16:16/רש"י על בראשית ט״ז:ט״ז

1'ואברם בן שמנים שנה וגו AND ABRAM WAS FOURSCORE AND SIX YEARS OLD etc. — This is written to Ishmael’s credit, pointing out that he was thirteen years old when he was circumcised (see Genesis 17:25) and yet he raised no objection.