Exodus 4:18-23

Then Moses went away and returned to Jethro his father-in-law, and said to him, “Please, let me go back so that I may return to my relatives in Egypt, and see if they are still alive.” And Jethro said to Moses, “Go in peace.” Then the LORD said to Moses in Midian, “Go back to Egypt, for all the men who were seeking your life [for killing the Egyptian] are dead.” [Ex 2:11, 12] So Moses took his wife [Zipporah] and his sons [Gershom and Eliezer] and seated them on donkeys, and returned to the land of Egypt. Moses also took the staff of God in his hand. The LORD said to Moses, “When you return to Egypt, see that you perform before Pharaoh all the wonders (miracles) which I have put in your hand, but I will harden his heart and make him stubborn so that he will not let the people go. Then you shall say to Pharaoh, ‘Thus says the LORD, “Israel is My son, My firstborn. So I say to you, ‘Let My son go so that he may serve Me’; and if you refuse to let him go, behold, I will kill your son, your firstborn.” ’ ”