What is the significance of Moshe's actions in this Pasuk?
Rashi #1 (citing Avodah-Zarah, 44a) and Rashbam: He was examining them like Sotos - to discover who had sinned without witnesses and without warning. 1
Rashi #3 (in Chukas, 19:9, citing R. Moshe ha'Darshsn): The Eigel contaminated all those who came into contact with it; and they became purified via its ashes, as the Torah writes "Vayizer al P'nei ha'Mayim". 2
Rashi #2 (in Balak, 25:6): The Torah is informing us that he stood up to six hundred rhousand people.
Ramban: He did this to denigrate the calf - by grinding it up and making them absorb it into their stomachs, from where they would later exude it when they defacated. 3
Targum Yonasan: Whoever donated a golden vessel towards the Golden Calf and drank some of the water that Moshe made them drink, a sign appeared on his face - and all those with the sign were killed by the B'nei Levi.
Rashi: Who then died the death of a Sotah. If there were witnesses and warning, they died by the sword (at the hands of the B'nei Levi. Refer to 32:27:5:1-2), like the inhabitants of an Ir ha'Nidachas ? since they were many (See Sifsei Chachamim); whereas if there were witnesses but no warning, they were smitten by a plague.
Rashi in Chukas, Bamidbar, 19:9 (citing R. Moshe ha'Darshan): In similar fashion, the ashes of the Parah Adumah rendered Tamei those who dealt with it on the one hand, and purified those wwho were Tamei, on the other.
In keeping with the Pasuk in Yeshayah, 30:22 (Ramban).
QUESTIONS ON RASHI
Rashi writes that those who served the Eigel died. Then why does the Torah writes in Pasuk 34 "u've'Yom Pakdi u'Fakadti aleihem Chatasam"?
Rosh (in Pasuk 7) #1: Those who could have protested, and did not, were not killed; Hashem would punish punish later. 1
Rosh (in Pasuk 7) #2: Those who said "Eileh Elokecha Yisrael asher He'elucha me'Eretz Mitzrayim" (Pasuk 4), but did not prostrate themselves, would be punished later. Had they said "He'elcha" (singular), they would all have perished [immediately]. By saying "He'elucha" (plural) they combined folly (the Eigel) with Hashem. One who does so is uprooted from the world; it was better for them not to die immediately.
Moshav Zekenim (in Pasuk 11): When Moshe ascended [the second time], he said 'I killed whom I was able, but there are strongarms that I cannot judge!' Hashem said, I will punish them in their time, with the Meraglim. In between, a Tzadik can be born to one who served idolatry - if he honored or benefited a Chacham. 2
Rosh: This is difficult, since Chur protested, and he was killed! (Why is this difficult? Presumably, Chur protested against many sinnesrs who were stronger than him. But someone who saw an individual serving could protest without danger, especially if he was stronger than the sinner - PF).
Like we find by the wicked idolater Izevel whose daughter married Yehoram ben Yehoshafat, from whom there came Mashi'ach.
Rashi writes that if there were witnesses and warning, they died by the sword, like Anshei Ir ha'Nidachas. But Anshei Ir ha'Nidachas did not apply (since the majority did not serve)! And if it did apply, why was their property not destroyed?