Sh’mot 12:37-38, it says that 600,000 men left Mitzraim. Verse 38 says a mixed crowd also left with them. Who would this mixed crowd be? How did this crowd relate to worship and mitzvots given to Yisrael?
These people, referred to in Hebrew as the “Erev Rav”, were Egyptians who were impressed by the God of Israel and wanted to join the People of Israel, and according to some ancient versions of the midrash, actually converted. Yet they hadn’t really left their idolatry and “old ways” behind, and according to the Oral tradition, they played a major role among the idolaters who served the golden calf and the complainers, during the 40 years in the desert.