'Bear Witness' in the Bible

I, Jesus, have sent my messenger, to bear witness unto you of these things, for the assemblies. I, am the Root and the Offspring of David, the bright and the morning Star.

I, bear witness, unto every one that heareth the words of the prophecy of this scroll: - If anyone shall lay aught upon them, God, will lay upon him, the plagues which are written in this scroll;