Martin Luther hated Jewish people. This is what he said about them in his book. This isn't slander.
Some of the things he said about Jews like Jesus Christ are:
“an idle and lazy people, such a useless, evil, pernicious people, such blasphemous enemies of God.”
“we let them get rich on our sweat and blood, while we remain poor and they suck the marrow from our bones.”
Martin did not stop with verbal attacks against Jews, but he also made many calls to violence as well:
"set fire to their synagogues or schools and to bury and cover with dirt whatever will not burn."
“their houses also be razed and destroyed.”
“all their prayer books and Talmudic writings, in which such idolatry, lies, cursing, and blasphemy are taught, be taken from them.”
“rabbis be forbidden to teach henceforth on pain of loss of life and limb.”
“safe-conduct on the highways be abolished completely for the Jews.”
“usury should be prohibited to them, and that all cash and treasure of silver and gold be taken from them and put aside for safekeeping.”
“putting a flail, an ax, a hoe, a spade, a distaff, or a spindle into the hands…letting them earn their bread in the sweat of their brow.”
“if we wish to wash our hands of the Jews’ blasphemy and not share in their guilt, we have to part company with them. They must be driven from our country…like mad dogs.”