Exodus 4:22-23

New King James Version

²² Then you shall ^(A)say to Pharaoh, ‘Thus says the Lord: ^(B)“Israel is My son, ^(C)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 ^(D)I will kill your son, your firstborn.” ’ ”