Vayera 21:9–21 speaks repeatedly of Hagar's son without once naming him. In no particular order, Rashi (:17), pseudo-Yonasan (:11), the Rav miBartinura (:14), Ramban (:9), Chizkuni (:14), Toldos Yitzchak (R' Yitzchak Karo), and Ralbag (beur hamilos :17) mention in passing, as if it's obvious, that this was Yishmael, and, indeed, we know of no other son of Hagar's. I wonder, though,
- whether any Jewish commentaries suggest that this was not Yishmael, and
- whether there's indication from the text of the Chumash (besides our not knowing of any other son of Hagar's) that this was Yishmael.