Exodus 4:21-23

New King James Version

²¹ And the Lord said to Moses, “When you go back to Egypt, see that you do all those ^(A)wonders before Pharaoh which I have put in your hand. But ^(B)I will harden his heart, so that he will not let the people go. ²² Then you shall ^(C)say to Pharaoh, ‘Thus says the Lord: ^(D)“Israel is My son, ^(E)My firstborn. ²³ So I say to you, let My son go that he may serve Me. But if you refuse to let him go, indeed ^(F)I will kill your son, your firstborn.” ’ ”