1)
What is the Torah referring to when it writes that Moshe, Aharon and Kol Adas B'nei Yisrael did all that Hashem commanded them?
1.
Rashi: Moshe stood them, Aharon waved them 1 and Yisrael leaned their hands on them.
2.
Seforno: Between them they helped the Levi'im to do everything that needed to be done regarding shaving, washing their clothes and bringing their Korban.
3.
Moshav Zekenim (citing R. Eliezer of Garmaiza): The Levi'im did not want to shave themselves. All Yisrael helped and shaved them Bal Korcham (against their will).
2)
Why does the Pasuk repeat "Kein Asu lahem B'nei Yisrael"?