Sforno on Genesis 16:15/ספורנו על בראשית ט״ז:ט״ו

1שם בנו אשר ילדה הגר ישמעאל, he was aptly called by that name both from Avram's point of view and from Hagar's point of view. Avraham prayed on behalf of his son Yishmael in 17,20, whereas Hagar's prayer had been heard as confirmed to her by the angel.