Exodus 4:21

17You shall take this rod in your hand, with which you shall do the signs.”

18Moses went and returned to Jethro his father-in-law, and said to him, “Please let me go and return to my brothers who are in Egypt, and see whether they are still alive.” Jethro said to Moses, “Go in peace.”

19The LORD said to Moses in Midian, “Go, return into Egypt; for all the men who sought your life are dead.”

20Moses took his wife and his sons, and set them on a donkey, and he returned to the land of Egypt. Moses took God’s rod in his hand.

21The LORD said to Moses, “When you go back into Egypt, see that you do before Pharaoh all the wonders which I have put in your hand, but I will harden his heart and he will not let the people go.

22You shall tell Pharaoh, ‘The LORD says, Israel is my son, my firstborn,

23and I have said to you, “Let my son go, that he may serve me;” and you have refused to let him go. Behold, I will kill your firstborn son.’”

24On the way at a lodging place, the LORD met Moses and wanted to kill him.

25Then Zipporah took a flint, and cut off the foreskin of her son, and cast it at his feet; and she said, “Surely you are a bridegroom of blood to me.”