Exodus 1:11-14

So they appointed taskmasters over them to afflict them with hard labor. And they built for Pharaoh storage cities, Pithom and Raamses. But the more they afflicted them, the more they multiplied and the more they spread out, so that they were in dread of the sons of Israel. The Egyptians compelled the sons of Israel to labor rigorously; and they made their lives bitter with hard labor in mortar and bricks and at all kinds of labor in the field, all their labors which they rigorously imposed on them.