Isaiah 66:16
"For by fire and by his sword will the LORD plead with all flesh: and the slain of the LORD shall be many."
Cross References (ranked by relevance)
Isaiah 30:30
And the LORD shall cause his glorious voice to be heard, and shall shew the lighting down of his arm, with the indignation of his anger, and with the flame of a devouring fire, with scattering, and tempest, and hailstones.
Isaiah 27:1
In that day the LORD with his sore and great and strong sword shall punish leviathan the piercing serpent, even leviathan that crooked serpent; and he shall slay the dragon that is in the sea.