A recent theory has proposed that Kūkai (空海) was not the author of Benkenmitsu nikyōron (弁顕密二教論) based on the absence of this text in An’nen’s (安然) works. This paper cites passages from the Benkenmitsu nikyōron appearing in Kyōnichi’s (教日) Jubodaishinkai gishiki (授菩提心戒儀式) (Tenri Central Library), written in 871 within An’nen’s lifetime (841–915), therefore suggesting that the author of the text was Kūkai.
The Chinese Tripitaka preserved in Iwayaji (岩屋寺) consists of 5,463 books in 548 boxes, of which 5,157 books are the Sixi Edition (思渓版), more precisely, the later Sixi Edition printed after the massive repair of woodblocks during the Jiaxi (嘉熙; 1237–1240) and Chunyou (淳祐; 1241–1252) eras. The remaining 195 books are Japanese manuscripts, while 111 books are Japanese printed editions.
This collection of books of the Sixi Edition was brought to Iwayaji by Uemon-no-jo Morimitsu (右衛門尉盛光) as his endowment in 1451 (宝徳3年). We know from the colophon of books that the collection previously belonged to the Kaiden’in (開田院) in 1281 (弘安4年), and then became a property of the Kozanji (高山寺) from 1293 (永仁元年) to 1343 (康永2年). As another piece of evidence, we find detailed kunten (訓点) or guiding marks for rendering Chinese into Japanese, added by Kyōben (経弁; 1246–1326), the third head priest of Kōzanji Jūmujin’in (高山寺十無尽院), in all volumes of the Daśabhūmivyākhyāna (十地経論). They are worthy materials for research on Huayan (華厳) studied in Kōzanji.