“And the Egyptians came to Pharaoh, and he told them to do as Joseph tells them”
Joseph told the Egyptians to be circumcised. Those 130 years of Jewish subjugation in Egypt correspond to the 130 years that Adam was separated from his wife Eve. For all those years, Adam was causing the birth of souls that needed correction.
These souls came back at the time of the Flood and later, at the time Dispersion, but instead of correction they kept repeating the same mistake. Now Joseph saw that they were reborn as Egyptians, and started their correction process. It was these people whom he later moved from city to city, for the same purpose. They are called “people of the sons of Israel.” They lived in their cities, and there behaved as Jews. Jacob, too, was accepting converts, and all these lived as Jews.
It is for these souls that Jews had to go down to Egypt, in order to bring them back. They constituted the mixed multitude.
In the next generation, the sparks of these souls came back as Jews. Now their correction process involved hard labor for 130 years.
Art: Hans Holbein - Adam and Eve. 1517