Exodus 11:4-8

Then Moses said, “Thus says the LORD: ‘At midnight I am going out into the midst of Egypt, and all the firstborn in the land [the pride, hope, and joy] of Egypt shall die, from the firstborn of Pharaoh who sits on his throne, to the firstborn of the slave girl who is behind the hand-mill, and all the firstborn of cattle as well. There shall be a great cry [of heartache and sorrow] throughout the land of Egypt, such as has never been before and such as shall never be again. But not even a dog will threaten any of the Israelites, whether man or animal, so that you may know [without any doubt] and acknowledge how the LORD makes a distinction between Egypt and Israel.’ All these servants of yours will come down to me and bow down before me, saying, ‘Get out, you and all the people who follow you.’ After that I will leave.” And he left Pharaoh in the heat of anger.