Exodus 4:20-26

4:20 Then Moses took his wife and sons and put them on a donkey and headed back to the land of Egypt, and Moses took the staff of God in his hand. 4:21 The Lord said to Moses, “When you go back to Egypt, see that you do before Pharaoh all the wonders I have put under your control. But I will harden his heart and he will not let the people go. 4:22 You must say to Pharaoh, ‘Thus says the Lord, “Israel is my son, my firstborn, 4:23 and I said to you, ‘Let my son go that he may serve me,’ but since you have refused to let him go, I will surely kill your son, your firstborn!”’”

4:24 Now on the way, at a place where they stopped for the night, the Lord met Moses and sought to kill him. 4:25 But Zipporah took a flint knife, cut off the foreskin of her son and touched it to Moses’ feet, and said, “Surely you are a bridegroom of blood to me.” 4:26 So the Lord let him alone. (At that time she said, “A bridegroom of blood,” referring to the circumcision.)