In November, 813, he made a request to Kukai to borrow 'Rishushakkyo,' but Kukai refused by indicating that 'it can be obtained not by studying the words but by practicing and training,' and after that, there were no more communications between them because of differences in their opinions.
813年11月、最澄が「理趣釈経」の借用を申し出たが、空海は「文章修行ではなく実践修行によって得られる」との見解を示して拒絶、以後交流は相容れなかった。