The following is from the web page Luther, Exposing the Myth, under the heading "On Reason":
“Reason is the devils handmaid and does nothing but blaspheme and dishonor all that God says or does”[Against the Heavenly Prophets, On Images and the Sacraments].
This is another Luther quote allegedly denigrating "reason" (a similar quote was discussed here). Luther Exposing the Myth says their stated purpose is to show that "from Luther’s own words we shall see him for what he really was, that is a rebellious apostate, who abandoned the faith and led many into apostasy from God under the guise of “reformation” in order to follow his perverse inclinations." With this quote, they attempt to show Christ exhorted his hearers to use reason, while Luther did the opposite.
This "reason" comment from Luther is one of many similar statements peppered throughout his writings. Lutheran theologian Siegbert Becker begins his treatment on Luther and reason with the following comments from Luther:
Reason is a big red murderess, the devil's bride, a damned whore, a blind guide, the enemy of faith, the greatest and most invincible enemy of God.
Such comments have been seized upon by many. Becker then contrasts these statements with the following from Luther:
Reason is God's greatest and most important gift to man, of inestimable beauty and excellence, a glorious light, a most useful servant in theology, something divine. [Siegbert Becker,The Foolishness of God (Milwaukee: Northwestern Publishing House, 1999, p. 1].
These later comments have not been seized upon by many. Obviously, there's a lot more going on than Luther Exposing the Myth expresses by using a single out of context quote. Luther Exposing the Myth at least accurately identified the treatise from which it took the quote, Against the Heavenly Prophets, On Images and the Sacraments. Other than that, this obscure quote is a typical propaganda hit: ignoring context, history, and theological presuppositions.
Against the Heavenly Prophets (1525) was written against Luther's former colleague Andreas Bodenstein von Karlstadt. In this treatise, Luther expresses (among other things) his harsh disagreement with Karlstadt over the sacrament of the Lord's Supper. Karlstadt held the body and blood of Christ are not in the sacrament. Luther argues against Karlstadt's Biblical argumentation for a number of pages, and then states:
Let this be our answer to the arguments and reasons that Dr. Karlstadt presents for his dream from Scripture. They were threefold. First, a capital letter is found in some books, not all. Second, there was a punctuation mark. Third, the dear touto. What wonderful arguments, which no one would use except such heavenly prophets, who hear the voice of God. A fourth now is, that he cannot present a single verse of Scripture in his favor. This is the most damaging argument and will forever remain so. I shall not overthrow it but will rather strengthen it. Furthermore he teaches us what Frau Hulda, natural reason, has to say in the matter, just as if we did not know that reason is the devil’s prostitute and can do nothing else but slander and dishonor what God does and says. But before we answer this arch-prostitute and devil’s bride, we first want to prove our faith, not by setting forth capitals or periods or touto tauta but by clear, sober passages from Scripture which the devil will not overthrow [LW 40:174]
Luther's Works explain the reference to Frau Hulda:
In Germanic mythology, Frau Hulda is the name of the leader of a group of elfin creatures who were looked upon as the instigators of good and evil among men. Like them Frau Hulda is of a capricious nature, now friendly, now hostile especially in times when disorder arises among men. She may therefore be regarded as a personification of order and clever reasoning. However, in matters of faith Luther looked upon reason as seductive, hence as “the devil’s prostitute.”
Luther doesn't begin to delve into Karlstadt's arguments from "reason" until later in the treatise (LW 40:192). Luther's arguments presented previously actually use "reason' in the sense that Luther is arguing from a grammatical and exegetical basis. When he attacks Karlstadt for using "reason," he's attacking him for attempting to explain Biblical data rationally. For Luther, reason can only say bread is bread. For Luther though, only the heart of faith can grasp Christ's words concerning the bread "this is my body." The senses will only lead one to believe that bread is bread.
In this instance, Luther actually is arguing for a doctrine Luther Exposing the Myth would adhere to. Such is what happens when a context is ignored. This type of miscitation shows that Romanists who put together web pages like Luther Exposing the Myth don't actually care about truth. They accuse of Protestants of "overlooking" certain citations from Luther, but in actuality, it is they who overlook doing the most basic task: reading a context truthfully and accurately.