Exodus 1:9

6 And Joseph died, and all his brethren, and all that generation.

7 And the children of Israel were fruitful, and increased abundantly, and multiplied, and waxed exceeding mighty; and the land was filled with them.

8 Now there arose a new king over Egypt, who knew not Joseph.

9 And he said unto his people, Behold, the people of the children of Israel are more and mightier than we:

10 come, let us deal wisely with them, lest they multiply, and it come to pass, that, when there falleth out any war, they also join themselves unto our enemies, and fight against us, and get them up out of the land.

11 Therefore they did set over them taskmasters to afflict them with their burdens. And they built for Pharaoh store-cities, Pithom and Raamses.

12 But the more they afflicted them, the more they multiplied and the more they spread abroad. And they were grieved because of the children of Israel.