http://www.jewishvirtuallibrary.org/jsource/anti-semitism/Luther_on_Jews.html
At the beginning of his career, Luther was apparently sympathetic to Jewish resistance to the Catholic Church. He wrote, early in his career:
The Jews are blood-relations of our Lord; if it were proper to boast of flesh and blood, the Jews belong more to Christ than we. I beg, therefore, my dear Papist, if you become tired of abusing me as a heretic, that you begin to revile me as a Jew.
But Luther expected them to convert to his purified Christianity. When they did not, he turned violently against Jews.
It is impossible for modern people to read the horrible passages below and not to think of the burning of synagogues in November 1938 on Kristallnacht. Nor would one wish to excuse Luther for this text.
A number of points must, however, be made. The most important concerns the language used. Luther used violent and vulgar language throughout his career....
...First to set fire to their synagogues or schools and to bury and cover with dirt whatever will not burn, so that no man will ever again see a stone or cinder of them. This is to be done in honor of our Lord and of Christendom, so that God might see that we are Christians, and do not condone or knowingly tolerate such public lying, cursing, and blaspheming of his Son and of his Christians. For whatever we tolerated in the past unknowingly and I myself was unaware of it will be pardoned by God. But if we, now that we are informed, were to protect and shield such a house for the Jews, existing right before our very nose, in which they lie about, blaspheme, curse, vilify, and defame Christ and us (as was heard above), it would be the same as if we were doing all this and even worse ourselves, as we very well know.
Second, I advise that their houses also be razed and destroyed. For they pursue in them the same aims as in their synagogues. Instead they might be lodged under a roof or in a barn, like the gypsies. This will bring home to them that they are not masters in our country, as they boast, but that they are living in exile and in captivity, as they incessantly wail and lament about us before God.
Third, I advise that all their prayer books and Talmudic writings, in which such idolatry, lies, cursing and blasphemy are taught, be taken from them. (remainder omitted)
Fourth, I advise that their rabbis be forbidden to teach henceforth on pain of loss of life and limb...