Vom Schem Hamphoras, full title: Vom Schem Hamphoras und vom Geschlecht Christi (Of the Unknowable Name and the Generations of Christ), was a book written by German Reformation leader Martin Luther in 1543, in which he equated Jews with the Devil and described them in vile language. Schem Hamphoras is the Hebrew rabbinic name for the ineffable name of God, the tetragrammaton. Luther's use of the term was in itself a taunt and insult to Jewish sensitivities. He wrote the tract several months after publishing On the Jews and Their Lies. In the book he wrote: