Genesis 49:3

“But he shall recognize the firstborn, the son of the unloved, by giving him a double portion of all that he has, for he is the first of his vigor; the legal judgment for the firstborn belongs to him.

“May Reuben live and not die, Nor his men be few.”

So He struck all the firstborn in Egypt, The first of their vigor in the tents of Ham.

He also struck down all the firstborn in their land, The first of all their vigor.

“And to the angel of the church in Laodicea write: This is what the Amen, the faithful and true Witness, the Beginning of the creation of God, says: