I guess I'll provide some literature on the subject, since it's so outrageous: https://en.wikipedia.org/wiki/Medieval_antisemitism

Also take note at how the classical 'wizard' character looks like a Jew... Big beard, hairy, robbed, silly hat, spectacles.... Again, the Jew's were believed to be sorcerers, which were particularly disliked by the Christian peoples, 'abhour the witch', 'Suffer not the Unclean'...

I'm a collector of obscure arcana, btw...!