Exodus 4:18-4:31
Moses went back to his father-in-law Jether and said to him, "Let me go back to my kinsmen in Egypt and see how they are faring." And Jethro said to Moses, "Go in peace." The Lord said to Moses in Midian, "Go back to Egypt, for all the men who sought to kill you are dead." So Moses took his wife and sons, mounted them on an ass, and went back to the land of Egypt; and Moses took the rod of God with him.
And the Lord said to Moses, "When you return to Egypt, see that you perform before Pharaoh all the marvels that I have put within your power. I, however, will stiffen his heart so that he will not let the people go. Then you shall say to Pharaoh, 'Thus says the Lord: Israel is My first-born son. I have said to you, "Let My son go, that he may worship Me," yet you refuse to let him go. Now I will slay your first-born son.'"
At a night encampment on the way, the Lord encountered him and sought to kill him. So Zipporah took a flint and cut off her son's foreskin, and touched his legs with it, saying, "You are truly a bridegroom of blood to me!" And when He let him alone, she added, "A bridegroom of blood because of the circumcision."
The Lord said to Aaron, "Go to meet Moses in the wilderness." He went and met him at the mountain of God, and he kissed him.
Moses told Aaron about all the things that the Lord had committed to him and all the signs about which He had instructed him. Then Moses and Aaron went and assembled all the elders of the Israelites. Aaron repeated all the words that the Lord had spoken to Moses, and he performed the signs in the sight of the people, and the people were convinced. When they heard that the Lord had taken note of the Israelites and that He had seen their plight, they bowed low in homage.