Exodus 1:11-14

So they put slave masters over them to oppress them with forced labor, and they built Pithom and Rameses as store cities for Pharaoh. But the more they were oppressed, the more they multiplied and spread; so the Egyptians came to dread the Israelites and worked them ruthlessly. They made their lives bitter with harsh labor in brick and mortar and with all kinds of work in the fields; in all their harsh labor the Egyptians worked them ruthlessly.