Exodus 4:15-25

15 And thou shalt speak unto him and put words in his mouth; and I will be with thy mouth and with his mouth and will teach you what ye shall do.
16 And he shall be thy spokesman unto the people; and he shall be unto thee as thy mouth, and thou shalt be unto him as God.
17 And thou shalt take this rod in thy hand with which thou shalt do the signs.
18 Thus Moses went and returned unto Jethro, his father-in-law, and said unto him, I shall go now and return unto my brethren who are in Egypt and see whether they are yet alive. And Jethro said to Moses, Go in peace.
19 And the LORD also said unto Moses in Midian, Go, return into Egypt, for all the men are dead who sought thy life.
20 Then Moses took his wife and his sons and set them upon an ass, and he returned to the land of Egypt; and Moses took the rod of God in his hand.
21 And the LORD said unto Moses, When thou goest to return into Egypt, see that thou do all those wonders before Pharaoh, which I have put in thine hand; but I will harden his heart, that he shall not let the people go.
22 And thou shalt say unto Pharaoh, The LORD hath said thus: Israel is my son, even my firstborn.
23 And I have said unto thee, Let my son go that he may serve me, but thou hast refused to let him go; therefore, behold, I will slay thy son, even thy firstborn.
24 And it came to pass by the way in the inn, that the LORD met him and sought to kill him.
25 Then Zipporah took a sharp flint and cut off the foreskin of her son and cast it at his feet, saying, Surely a bloody husband art thou to me.