Psalm 136:10
"To him that smote Egypt in their firstborn: for his mercy endureth for ever:"
Cross References (ranked by relevance)
And it came to pass, that at midnight the LORD smote all the firstborn in the land of Egypt, from the firstborn of Pharaoh that sat on his throne unto the firstborn of the captive that was in the dungeon; and all the firstborn of cattle.
And smote all the firstborn in Egypt; the chief of their strength in the tabernacles of Ham:
Who smote the firstborn of Egypt, both of man and beast.
He smote also all the firstborn in their land, the chief of all their strength.
For I will pass through the land of Egypt this night, and will smite all the firstborn in the land of Egypt, both man and beast; and against all the gods of Egypt I will execute judgment: I am the LORD.
Through faith he kept the passover, and the sprinkling of blood, lest he that destroyed the firstborn should touch them.