Exodus 4:22-24

American Standard Version

²² And thou shalt say unto Pharaoh, Thus saith Jehovah, Israel is my son, my first-born: ²³ and I have said unto thee, Let my son go, that he may serve me; and thou hast refused to let him go: behold, I will slay thy son, thy first-born. ²⁴ And it came to pass on the way at the lodging-place, that Jehovah met him, and sought to kill him.