parshanut torah comment - How did Moshe know he was Jewish?

Shemot 2:11 says how Moshe went out to see the suffering of his people:

וַיְהִ֣י ׀ בַּיָּמִ֣ים הָהֵ֗ם וַיִּגְדַּ֤ל מֹשֶׁה֙ וַיֵּצֵ֣א אֶל־אֶחָ֔יו וַיַּ֖רְא בְּסִבְלֹתָ֑ם וַיַּרְא֙ אִ֣ישׁ מִצְרִ֔י מַכֶּ֥ה אִישׁ־עִבְרִ֖י מֵאֶחָֽיו׃

And it came to pass in those days, when Moses was grown up, that he went out unto his brethren, and looked on their burdens; and he saw an Egyptian smiting a Hebrew, one of his brethren.

But growing up in the king's palace as an Egyptian, how would he know that he was of Bnei Yisrael?

The Ramban explains that they (the Egyptians) told him, but why would they do that? "Hey, i know you think you're the prince, but actually, your people are those slaves..."

Totally lame source, but The Prince of Egypt's explanation is that he saw it in a dream, and then Pharaoh admitted it. Could this be what Ramban meant?

Answer

Four possible ways for Moshe to have known he was Jewish:

• His mother/family told him.


• The daughter of Pharaoh told him.


• He found out by supernatural means.


• It was just known, generally.

(@WAF's answer covers the last possibility, as well as the first in more detail; I mention them here only for completeness, and am answering separately to add the middle two as well as a source for the first.)

Abarbanel offers the first answer, that Moshe learned of his origins from his mother, who raised him for the first part of his life:

לפי שמשה תמיד דבקה נפשו ביוכבד אשר גדלתו, ובבניה. ואחרי שנתגדל, ידע מהם אמתת ענינו, ושהוא מילדי העברי ... והנה משה, כשנתקיים בשכלו, וידע על נכון את אביו ואת אמו והכיר את אחיו, חם לבו בקרבו לראות ענינם.

Moshe was always connected to Yocheved who raised him, and to her children, and after he grew up, he knew from them the truth of the matter, that he was a Hebrew child.

The 'מעשי ה disagrees with this suggestion, and believes that Pharaoh's daughter told him:

עוד כתב שמשה בהיותו בבית יוכבד ידע מולדתו, ואני לדעתי אין הדברים כן. וטרם בואנו אל הנרצה בענין זה נקדים שיפלא מה שאמר הכתוב ויהי לה לבן, כי לא מצאנו בכל הסיפור מה שנתנהגה עמו כאם לבן ואם כן מה הוצרך לומר שהיה לה לבן, ועוד יפלא שכיון ששמו של משה נגזר מהויתו משוי מן המים א"כ תכף כשמשתה אותו מן המים היה לה לקוראו בשם זה. אבל נראה שבאשר הביאה יוכבד את משה לבת פרעה כאשה מניקת שמביאה הילד לאמו, חשב משה שהוא בנה של בת פרעה, וזהו שנאמר ויהי לה לבן שמשה חשב שהיא אמו, וע"כ קראה אותו אז משה בלשון הקודש כדי שידע משה שמילדי העברים הוא ושאינה בנה, וזהו שהסמיך הכתוב ואמר ויצא אל אחיו כאלו יאמר שאמר שנודע אליו היותו מילדי העברים יצא אל אחיו.

It's also been written that when Moshe was in the house of Yocheved he knew the details of his birth, but in my opinion this is not correct. ... It seems to me that when Yocheved brought Moshe to the daughter of Pharaoh, as a nursemaid brings a child to his mother, Moshe thought that he was the son of Pharaoh's daughter, and this is the meaning of ויהי לה לבן, "and he was to her a son;" and to correct this impression of his, she then named him Moshe, in Hebrew, that he should know that he is a child of the Hebrews, and not her son.

The שפתי כהן offers a possibility that actually resembles your dream-suggestion somewhat: He proposes that "And Moshe grew up" may be understood as "grew into prophecy" (by parallel with a similar description of Shmuel) and says that it was by his newly-acquired prophetic power that he knew that the enslaved people were his brothers.

עוד נאמר כי ויגדל הוא בנבואה, כמו שאמר בשמואל (שמואל-א ג' י"ט) ויגדל שמואל וה' היה עמו שהיה גדול לנבואה כן כאן ויגדל שניבא וידע שאותם שהם בגלות הם אחיו

He prophesied, and knew that the exiled ones were his brothers.

(Credit for neat summary of possibilities goes to R'Y.Kolatch, who gave a shiur including this.)