Exodus 4:21-23

Wycliffe Bible

²¹ And the Lord said to him turning again into Egypt, See, that thou do all the wonders, which I have put in thine hand, before Pharaoh; I shall make hard his heart, and he shall not deliver the people; (And the Lord said to him as he returned to Egypt, See, that thou do all the miracles before Pharaoh, which I have put in thy hand; but I shall harden his heart, and he shall not let the people go;)

²² and thou shalt say to him, The Lord saith these things, My first begotten son is Israel (Israel is my first-born son);

²³ I said to thee, Deliver thou my son, that he serve me, and thou wouldest not deliver him; lo! I shall slay thy first begotten son. (I said to thee, Let my son go, so that he can worship me, but thou wouldest not let him go; so now I shall kill thy first-born son.)