Psalm 105:36

“Reuben, you are my firstborn; My might and the beginning of my vigor, Preeminent in dignity and preeminent in strength.

“So I said to you, ‘Let My son go that he may serve Me’; but you have refused to let him go. Behold, I will kill your son, your firstborn.”’”

and all the firstborn in the land of Egypt shall die, from the firstborn of the Pharaoh who sits on his throne, even to the firstborn of the servant-girl who is behind the millstones; and all the firstborn of the cattle.

Now it happened at midnight that Yahweh struck all the firstborn in the land of Egypt, from the firstborn of Pharaoh who sat on his throne to the firstborn of the captive who was in the dungeon, and all the firstborn of cattle.

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

They set forth the words of His signs among them, And miracles in the land of Ham.

He struck the firstborn of Egypt, From man to beast.