"And Abraham returned to his young men" (Genesis 22:19) — Ishmael and Eliezer were disputing with one another. Ishmael was saying: Abraham will slaughter Isaac, and I will inherit him. And Eliezer said to him: You will not inherit, for he has already driven you out; but I am the son of his house, and I will inherit him. When Abraham returned to his young men, to the place where he had left them, and they did not see Isaac, they supposed that he had slaughtered him. They said to him: Isaac — where is he? He said to them: I have brought him to the house of Eber his teacher, to study Torah. Therefore it is said, "And Abraham returned" — that is to say, alone, and he did not mention Isaac. "And they rose up" — because he had said to them, "Stay here," therefore it says, "and they rose up." "And they went" — just as it was in Abraham's heart that Isaac was alive, so too they knew that Isaac was alive, for they believed the words of Abraham, since they knew that he does not lie.
Ishmael and Eliezer Quarrel Over Inheriting Isaac at the Akedah
Midrash Aggadah, Genesis 22:19
וישב אברהם אל נעריו. ישמעאל ואליעזר שהיו מדיינין זה עם זה, ישמעאל היה אומר אברהם ישחוט את יצחק ואני יורשו, ואליעזר אומר לו לא תירש שכבר גרשך, אבל אני בן ביתו ואירשנו, כיון ששב אברהם אל נעריו אל המקום אשר הניחם, ולא ראו יצחק, היו סבורים ששחטו, אמרו לו יצחק היכן הוא, אמר להם לבית עבר רבו הולכתיו ללמוד תורה, לכך נאמר וישב אברהם, כלומר לבדו ולא הזכיר יצחק: ויקמו. לפי שאמר להם שבו לכם לכך אמר ויקמו: וילכו. כשם שהיה בלבו של אברהם שיצחק היה חי, כך ידעו הם שיצחק חי שהאמינו לדברי אברהם שידעו שאינו מכזב: