These are the names of the sons of Israel (that is, Jacob) who moved to Egypt with their father, each with his family: Reuben, Simeon, Levi, Judah, Issachar, Zebulun, Benjamin, Dan, Naphtali, Gad, and Asher. In all, Jacob had seventy descendants in Egypt, including Joseph, who was already there.
In time, Joseph and all of his brothers died, ending that entire generation. But their descendants, the Israelites, had many children and grandchildren. In fact, they multiplied so greatly that they became extremely powerful and filled the land.
Eventually, a new king came to power in Egypt who knew nothing about Joseph or what he had done. He said to his people, “Look, the people of Israel now outnumber us and are stronger than we are. We must make a plan to keep them from growing even more. If we don’t, and if war breaks out, they will join our enemies and fight against us. Then they will escape from the country.”
So the Egyptians made the Israelites their slaves. They appointed brutal slave drivers over them, hoping to wear them down with crushing labor. They forced them to build the cities of Pithom and Rameses as supply centers for the king. But the more the Egyptians oppressed them, the more the Israelites multiplied and spread, and the more alarmed the Egyptians became.