Exodus 5:14

5:14 The Israelite foremen whom Pharaoh’s slave masters had set over them were beaten and were asked, “Why did you not complete your requirement for brickmaking as in the past – both yesterday and today?”

Exodus 11:5

11:5 and all the firstborn in the land of Egypt will die, from the firstborn son of Pharaoh who sits on his throne, to the firstborn son of the slave girl who is at her hand mill, and all the firstborn of the cattle.