Anyone know the meaning of this?

I believe it means that those who know Jesus, also prophesy.

The testimony of Jesus is two sided ... it is His Testimony and the testimony of Him, within us.The Spirit is also known as the Spirit of Jesus, of Truth, of Revelation, etc.. Here it is of "Prophecy", that the remnant or elect of The Revelation possess ...G4394προφητείαprophēteiaThayer Definition:1) prophecy1a) a discourse emanating from divine inspiration and declaring the purposes of God, whether by reproving and admonishing the wicked, or comforting the afflicted, or revealing things hidden; especially by foretelling future events1b) Used in the NT of the utterance of OT prophets1b1) of the prediction of events relating to Christ’s kingdom and its speedy triumph, together with the consolations and admonitions pertaining to it, the spirit of prophecy, the divine mind, to which the prophetic faculty is due1b2) of the endowment and speech of the Christian teachers called prophets1b3) the gifts and utterances of these prophets, especially of the predictions of the works of which, set apart to teach the gospel, will accomplish for the kingdom of ChristPart of Speech: noun feminineA Related Word by Thayer’s/Strong’s Number: from G4396 (“prophecy”)Citing in TDNT: 6:781, 952Which would make much sense, as this is written of those who go through the end days and Need the True Prophetic enabling to discern the times, events, people, beasts, false signs and wonders - heresies and all else that the end times holds, in order to be faithful unto the end as overcomers and not be deceived or given over to the strong delusion. Rev 1:2 Who bare record of the word of God, and of the testimony of Jesus Christ, and of all things that he saw. Rev 1:9 I John, who also am your brother, and companion in tribulation, and in the kingdom and patience of Jesus Christ, was in the isle that is called Patmos, for the word of God, and for the testimony of Jesus Christ. Rev 12:17 And the dragon was wroth with the woman, and went to make war with the remnant of her seed, which keep the commandments of God, and have the testimony of Jesus Christ. Rev 19:10 And I fell at his feet to worship him. And he said unto me, See thou do it not: I am thy fellow servant, and of thy brethren that have the testimony of Jesus: worship God: for the testimony of Jesus is the spirit of prophecy. Rev 19:11 And I saw heaven opened, and behold a white horse; and he that sat upon him was called Faithful and True, and in righteousness he doth judge and make war. Rev 19:12 His eyes were as a flame of fire, and on his head were many crowns; and he had a name written, that no man knew, but he himself. Rev 19:13 And he was clothed with a vesture dipped in blood: and his name is called The Word of God. Rev 19:14 And the armies which were in heaven followed him upon white horses, clothed in fine linen, white and clean. Rev 19:15 And out of his mouth goeth a sharp sword, that with it he should smite the nations: and he shall rule them with a rod of iron: and he treadeth the winepress of the fierceness and wrath of Almighty God. Rev 19:16 And he hath on his vesture and on his thigh a name written, KING OF KINGS, AND LORD OF LORDS.Neat ! Good question brother Murray. Very timely.