Exodus 4:18-23

So Moses went back home to Jethro, his father-in-law. “Please let me return to my relatives in Egypt,” Moses said. “I don’t even know if they are still alive.” “Go in peace,” Jethro replied. Before Moses left Midian, the LORD said to him, “Return to Egypt, for all those who wanted to kill you have died.” So Moses took his wife and sons, put them on a donkey, and headed back to the land of Egypt. In his hand he carried the staff of God. And the LORD told Moses, “When you arrive back in Egypt, go to Pharaoh and perform all the miracles I have empowered you to do. But I will harden his heart so he will refuse to let the people go. Then you will tell him, ‘This is what the LORD says: Israel is my firstborn son. I commanded you, “Let my son go, so he can worship me.” But since you have refused, I will now kill your firstborn son!’”