Siman 521

(78.) Regarding the virtue of one who innovates Torah — that it is a great rectification for immoral thoughts, as is explained elsewhere [Likutay Tinyana, Torah 105]. I myself heard from his holy mouth many many times that he greatly admonished to innovate in Torah. And he said it is a very great rectification for the past. And he said that even one word when one merits to innovate is also very good — for it is a very great rectification. He also said it is a great benefit for the souls of his forebears who have already passed away.