Revelation 2:16 in the King James Version
Repent; or else I will come unto thee quickly, and will fight against them with the sword of my mouth.
Context
15 So also you likewise have some who hold to the teaching of the Nicolaitans.
16 Repent therefore, or else I am coming to you quickly and I will make war against them with the sword of my mouth.
17 He who has an ear, let him hear what the Spirit says to the assemblies. To him who overcomes, to him I will give of the hidden manna, and I will give him a white stone, and on the stone a new name written which no one knows but he who receives it.