There's a popular understanding that the Gra asked R Chaim of Volozhin to write a sefer based on his teachings that would deal with many points that the sefer Tanya dealt with and this is the Nefesh HaChaim.
- Is there a source to this story?
- If not, is it a given that what R Chaim writes in his book is what the Gra himself held to be true?
They say the Gra... closed it after the first line because the standard version of the Gemara does not have the word Tanya.This seems apocryphal, especially in light of the fact that the Vilna Gaon himself sometimes introduces tannaitic statements in Bei'ur HaGr"a by adding the word tanya. – Fred Jul 07 '16 at 01:56