Whenever Moshe came before Pharaoh, Aharon accompanied him. So why does the Torah need to mention him independently?
Ramban (citing the Ibn Ezra): Because Pharaoh would shortly recall them, before expelling them both - the only time that he ever did that.
What did Moshe mean when he asked Pharaoh how long it would take to humble himself before Him?
Rashi: Pharaoh was already beginning to waver before Hashem's might, because he could not bear the devastation caused by the plagues. 1 The objective of the plagues, however, was (not to bring Pharaoh to his knees for fear of the punishment, but) to cause him to acknowledge Hashem. 2
Seforno: If even now, when Hashem had demonstrated His supremacy over the atmosphere (without which one cannot live for even one moment), Pharaoh could not bring himself to humble himself before Hashem, no plague on earth would bring that about; but perhaps a prolonged dosage of Makos would do the trick. Hence the question, "How long will it take ... "?
Elsewhere, Hashem is called "Elokei Yisrael." Why here did Moshe and Aharon call him "Elokei ha'Ivrim"?
Moshav Zekenim #1: The root of the name Yisrael is 'Serarah' (supremacy) - not appropriate as long as they were still slaves.
Moshav Zekenim #2: Since Yisrael retained their language, Hashem placed His Name upon them with the name of their language - 'Ivris.'
QUESTIONS ON RASHI
Rashi writes: "Lei'anos - As Targum translates, 'to be submissive,' from the word "Ani" (poor); [i.e.] you have refused to be poor and lowly before Me." How else might I have translated?
Gur Aryeh: "Lei'anos" could have meant 'suffering' ('Inuy' - meaning 'how long shall you refuse to suffer before Me'); or it could mean 'subjugation;' 1 but neither of these is what Hashem wanted of Pharaoh. He wanted Pharaoh to be humbled, and to submit. 2
Gur Aryeh: As in Bereishis 16:9.
We know this from grammar as well. Any expression of "Inuy" (suffering) will have a Dagesh in the letter Nun - which the word "Lei'anos" does not. (CS)
