Exodus 4:23
and I told you to let My son go so that he may worship Me. But since you have refused to let him go, behold, I will kill your firstborn son!’”
Berean Standard Bible
And I say unto thee, Let my son go, that he may serve me: and if thou refuse to let him go, behold, I will slay thy son, even thy firstborn.
and 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.’”