“Martin Luther was particularly anti-Semitic. His writings were precursors of twentieth-century National Socialist texts...”
Luther is an interesting case. In his early writings, he was actually quite philo-semitic. He had this very unrealistic expectation, though, that once his de-Romanized version of Christianity was presented to Jews, they’d eagerly convert en masse. He was bitterly disappointed when they didn’t follow through... hence the virulent anti-semitism of the later writings. In hindsight, you think, how could he have possibly thought that, well, they’ve held out for what, 1500 years, but *he* was the guy to convince them? Very hubristic little friar, that ML.
I haven't studied the matter, but there's apparently a case to be made that it's a work of forgery. Someone other than Luther wrote it, either to trade on his name, or to discredit him
One theory is that the book was written by an unknown rabbi, who sought to discredit Luther among the Jews, and thus stifle his conversion attempts.
A reason for this theory is that the book apparently denies the canonical status of Jeremiah, which Luther never denied.