Luther: My word is the word of Christ; my mouth is the mouth of Christ

Here's an obscure Luther quote compliments of the Catholic Answers Sacred Scripture forum:

My word is the word of Christ; my mouth is the mouth of Christ" (O'Hare PF. The Facts About Luther, 1916--1987 reprint ed., pp. 203-204). [Specifically, what Martin Luther wrote in German was ""Ich bin sehr gewiss, dass mein Wort nitt mein, sondern Christus Wort sei, so muss mein Mund auch des sein, des Wort er redet" (Luther, 682) - also translated as "I am confident that it is not my word, but Christ's word, so my mouth is His who utters the words"(God's words - the violence of representation. Universitatea din Bucuresti, 2002. http://www.unibuc.ro/eBooks/filologie/meanings/1.htm, September 25, 2003).]

Source
This paragraph appears to be a direct cut-and-paste from this webpage: Sola Scriptura or Prima Luther? What Did Martin Luther Really Believe About the Bible?, which is not a Roman Catholic source, but rather, as the author explains, "COGwriter is an abbreviation for Church of God (COG) writer. The term Church of God is used here to include those Sabbatarian (sabbath-keeping) churches that are faithful to apostolic Christianity (most generally, but not exclusively, those who came out of the pre-1986 Worldwide Church of God, and hold similar beliefs)." So, the Catholic Answers participant appears to be taking his information from a source that holds "After reading the Bible as an early teen it quickly became apparent to me that the Church of Rome no longer seemed to practice original biblical Christianity."

COG Writer states:

Martin Luther publicly taught that only the Bible should be used as doctrine. One of the rallying cries of his movement was sola Scriptura (translated in English as 'the Bible alone'). This is one of the major positions that many professing Protestants respect Martin Luther for. Although Martin Luther stated that he looked upon the Bible "as if God Himself spoke therein" he also stated, "My word is the word of Christ; my mouth is the mouth of Christ" (O'Hare PF. The Facts About Luther, 1916--1987 reprint ed., pp. 203-204).[Specifically, what Martin Luther wrote in German was ""Ich bin sehr gewiss, dass mein Wort nitt mein, sondern Christus Wort sei, so muss mein Mund auch des sein, des Wort er redet" (Luther, 682) - also translated as "I am confident that it is not my word, but Christ's word, so my mouth is His who utters the words"(God's words - the violence of representation. Universitatea din Bucuresti, 2002. http://www.unibuc.ro/eBooks/filologie/meanings/1.htm, September 25, 2003).] Did Martin Luther really revere and believe the Bible more than his own opinions? This article will quote Martin Luther extensively to assist the reader in answering that question.

This first bit of bibliographic data is "O'Hare PF. The Facts About Luther, 1916--1987 reprint ed., pp. 203-204." This quote in question is on page 204, and the immediate context flows over to page 205.  Father O'Hare states:

The Inspired Word of God was nothing to Luther when it could not be made to square with Lutheranism. He is prepared to assume the whole responsibility for the changes he made and believes he has the faculty of judging the Bible without danger of error. He believes he is infallible. "My word," says he, in an exhortation to his followers, "is the word of Christ: my mouth is the mouth of Christ." And to prove this, he indulges in a prophecy: he proclaims that "if his Gospel is preached but for two years, then Pope, bishops, cardinals, priests, monks, nuns, bells, belltowers, masses—rules, statues and all the vermin and riff-raff of the Papal government, will have vanished like smoke." Luther with all this flourish of trumpets proved himself a false prophet. 1 The Church that he thought would "vanish like smoke" is still in existence and now as ever cries out in the words of her Founder: "There will rise up false Christs and false prophets and they shall show signs and wonders to seduce, if it were possible, even the elect. Take ye heed, therefore: behold I have foretold you all things." St. Mark XIII, 22, 23.

O'Hare does not provide any documentation for this quote. The second bit of bibliographic data is a different English translation of the quote accompanied by the German original. The documentation given by COG writer makes reference to a web link that has long since vanished. That link was to a book by Dr. Mãdãlina Nicolaescu, Meanings of violence in Shakespeare's Plays. The chapter being cited is entitled, "God's words - the violence of representation." There the author states,

In the early days of the Reformation militant Protestants like Luther were convinced that God was using the apocalyptic sword against the false Roman Catholic Church, identified as Antichrist. The Protestants' belief in God's judgment over the papists was crucial in substantiating the new religious values and dogmas they were promoting. Representations of imminent providential violence against the "godless" were central to the othering strategies underpinning the constitution of the new religious subjectivity.

Martin Luther employed the visual image of God's sword coming out of his mouth to admonish his supporters not to use physical violence in defence of their faith. The reason Luther gave Christian faith, but that God's punishment will be much more devastating. Recourse to violence is not abandoned but the ways and means of its employment are redefined.

In one of his major writings - Eine treue Vormahnung Martini Luther zu allen Christen sich zu vorhüten für Aufruhr und Empörung (A Sincere Admonition by Martin Luther to all Christians to guard against all Insurrection and Rebellion) Luther gives a surprising twist to the traditional meanings attached to God's sword: he starts from the description of God's lethal breath in Isaiah (11.4) and Paul ( 2 Thessalonians 2.8.) and redefines it as words.

Physical violence is rejected in view of the superior efficacy of the violence of representation. Luther stresses over again that it is the violence of words and not that of physical weapons that can truly defeat and destroy the popish institution.

In Eine treue Vormahnung the relation between God's mouth and His sword is no longer one of contiguity but of identity. The sword is no longer an extension of the mouth like in Holbein's painting but the mouth incorporates the sword. The instrument of speech appropriates the lethal punishing capacity of the instrument of devine violence. Speech becomes synonymous with punishment and destruction.

Luther further revises the image and introduces his own mouth as an extension of God's mouth. Are we to understand that his mouth therefore takes the place of the double-edged sword in the picture? It definitely seems to incorporate God's sword. Luther expresses his confidence that his words are nothing less than God's words and indicates that he has appropriated the divine violence : "Ich bin sehr gewiss, dass mein Wort nitt mein, sondern Christus Wort sei, so muss mein Mund auch des sein, des Wort er redet" (Luther, 682) - ( "I am confident that it is not my word, but Christ's word, so my mouth is His who utters the words." My translation.)

Dr. Mãdãlina Nicolaescu refers to Luther's "A Sincere Admonition by Martin Luther to all Christians to guard against all Insurrection and Rebellion." This treatise can be found in WA 8: 676-687. At least two English translations exist: PE 3: 206-222 and LW 45: 51-74. The quote in question can be found in LW 45:66.

Context
As the title of Luther's treatise suggests, the emphasis is an admonition against physical violence. Here's a broader context of the quote in question:

Third. You are to let your mouth become such a mouth of the Spirit of Christ as St. Paul speaks of in the text quoted above, “Our Lord Jesus will slay him with the mouth of his Spirit.” This we do when we boldly continue the work that has been begun, and by speaking and writing spread among the people a knowledge of the rascality and deceit of the pope and the papists until he is exposed, recognized, and brought into disrepute throughout the world. For he must first be slain with words; the mouth of Christ must do it. In that way he will be torn from the hearts of men, and his lies recognized and despised. When he is gone from men’s hearts and so has lost their confidence, he is already destroyed. He can be handled better this way than with a hundred insurrections. By resort to violence we will do him no harm at all, but rather strengthen him, as many have experienced before. But the light of truth hurts him; when we contrast him with Christ, and his teaching with the gospel, that brings him down and utterly destroys him without any effort and exertion on our part. See what I have done. Have I not, with the mouth alone, without a single stroke of the sword, done more harm to the pope, bishops, priests, and monks than all the emperors, kings, and princes with all their power ever did before? And why? Because Daniel 8[:25] says, “By no human hand shall this king be broken”; and St. Paul says, “He will be destroyed by the mouth of Christ” [II Thess. 2:8]. Now every man—whether it be I or another—who speaks the word of Christ may boldly assert that his mouth is the mouth of Christ. I for my part am certain that my word is not mine, but the word of Christ; my mouth therefore must also be the mouth of him whose word it speaks.
Therefore, there is no need for you to demand an armed insurrection. Christ himself has already begun an insurrection with his mouth, one which will be more than the pope can bear. Let us follow that one, and carry on. What is now transpiring in the world is not our work. No mere man could possibly begin and carry on such an affair by himself. It has come thus far without my consideration and counsel; it will also be completed without my advice, and the gates of hell shall not stop it [Matt. 16:18]. A far different Man is the driving power; the papists do not see Him but lay the blame on us. However, they shall see for themselves very soon. The devil has for a long time feared the coming of these years; he smelled the pot boiling a long way off. He even issued many prophecies against it, some of which point to me, so I often stand amazed at his great cunning. Often he would have liked to kill me. Now he would like to see an armed insurrection develop which would hinder and bring into disrepute this spiritual insurrection. But, God willing, there should be and will be no such help for him. He must be destroyed “by no human hand” but “by the mouth” alone; nothing will prevent that.
Get busy now; spread the holy gospel, and help others spread it; teach, speak, write, and preach that man-made laws are nothing; urge people not to enter the priesthood, the monastery, or the convent, and hinder them from so doing; encourage those who have already entered to leave; give no more money for bulls, candles, bells, tablets, and churches; rather tell them that a Christian life consists of faith and love. Let us do this for two years, and you shall see what will become of pope, bishops, cardinals, priests, monks, nuns, bells, towers, masses, vigils, cowls, hoods, tonsures, monastic rules, statutes, and all the swarming vermin of the papal regime; they will all vanish like smoke. But if we fail to teach and spread this truth among the people so their hearts will no longer cling to these things, we will still have the pope with us, though we were to start a thousand insurrections against him. Just see what has been accomplished in this one single year, during which we have been preaching and writing this truth! See how the papists’ covers have shrunk in length and in breadth! The stationaries complain that they are starving to death. What will be the result if the mouth of Christ continues to thresh by his Spirit for two more years? This is what the devil would like to prevent by stirring up an armed insurrection. But let us be wise, thank God for his holy word, and be bold with our mouths in the service of this blessed insurrection.
Luther, M. (1999, c1962). Vol. 45: Luther's works, vol. 45 : The Christian in Society II (J. J. Pelikan, H. C. Oswald & H. T. Lehmann, Ed.). Luther's Works (45:67). Philadelphia: Fortress Press.

Conclusion
Contexts are such interesting things, aren't they? Where Father O'Hare would have his readers believe Luther thought he was infallible, in context, Luther is saying something far different. He's speaking of the power of the Word of God in the mouth of any believer.