Facts in Judaism
10 Things You Didn't Know About the Sin of the Golden Calf
Why doesn't the kohen gadol (high priest) enter the Holy of Holies on Yom Kippur in his golden garments? What was the sin of Yeravam the son of Nevat? Why were Jewish women given the holiday of Rosh Chodesh?

1. The Chet ha'egel (sin of the Golden Calf) was primarily committed by the eirev rav (the mixed multitude of Egyptians who joined the Jewish people on their way out of Egypt), but its impact was so deep and staggering that destruction was decreed upon the entire nation. Only after Moshe pleaded with Hashem for 40 days did Hashem relent and forgive them.
2. The people demanded of Chur, Miriam's son, to make the calf. He refused and was killed. His grandson, Betzalel, built the Tabernacle to atone for this sin.
3. Since Aharon did not want the people to be guilty of killing a priest and prophet, he tried to stall and prevent the creation of the calf. However, a satanic act occurred, and the calf formed itself from the golden jewelry, and it became impossible to prevent the people from sinning.
4. Some commentators believe that the death of Nadav and Avihu was Aharon's punishment for participating in this sin, even though it was against his will.
5. Moshe burned the calf, ground it into dust, and threw the dust into the stream that flowed from Mount Sinai. The Jewish people drank this water, like a woman who is suspected of committing adultery drinks from the bitter waters.
6. The Jews achieve purification through the parah adumah (red heifer): let the mother (the heifer) come and clean up after her son (the calf). The purification process also involves mixing the heifer's ashes with water, just as Moshe did with the calf.
7. The kohen gadol (high priest) does not enter the kodesh hakadashim (Holy of Holies) on Yom Kippur wearing his golden garments, so as not to invoke the sin of the Golden Calf. "The prosecutor cannot become the defender."
8. Despite the great pain caused to the Jewish people by the chet ha'egel, Yeravam, the son of Nevat, repeated this sin by making golden calves to prevent the people from Israel's Northern Kingdom from going to the Temple in Jerusalem (in the Southern Kingdom), against which Yeravam had rebelled. By causing the masses to sin for generations Yeravam is considered to be one of the worst kings, and the destruction of the Kingdom of Israel is attributed to him.
9. The prophet Hoshea prophesied, "Those who sacrifice men kiss calves," and thus noted that by worshiping the calf (instead of Hashem at the Temple in Jerusalem), the people eventually reached the point of sacrificing their sons and daughters to Baal. The moral deterioration began by disobeying the law and crumbled to the lowest possible level.
10. Chava caused Adam to sin, but the women of Israel rectified this sin by opposing the Golden Calf and not cooperating with the initiative to produce the calf. According to the Midrash (Pirkei D'Rabbi Eliezer 45), Jewish women were rewarded for this, and Rosh Chodesh became their special holiday, during which they refrain from work.