פירוש על שמות 12:38

ערב רב A MIXED MULTITUDE — a mingling of various nations who had become proselytes.

וצאן ובקר, of the mixed multitude who were leaving Egypt with the Israelites to take up residence among them together with all their belongings.

ערב רב, an expression describing a mixed assortment, as we find it in Psalms 106,35 ויתערבו בגוים, “they mixed freely with the gentiles, assimilated.”