Exodus 4:23
and I told you to let My son go so that he may worship Me. But you have refused to let him go, so I will kill your firstborn son!'"

Exodus 11:5
and every firstborn son in the land of Egypt will die, from the firstborn of Pharaoh who sits on his throne, to the firstborn of the servant girl behind the hand mill, as well as the firstborn of all the cattle.

Exodus 12:29
Now at midnight the LORD struck down every firstborn male in the land of Egypt, from the firstborn of Pharaoh, who sat on his throne, to the firstborn of the prisoner in the dungeon, as well as all the firstborn among the livestock.

Psalm 78:51
He struck all the firstborn of Egypt, the virility in the tents of Ham.

Psalm 105:36
Then He struck all the firstborn in their land, the firstfruits of all their vigor.

Psalm 135:8
He struck down the firstborn of Egypt, of both man and beast.