National Treasures & Important Cultural Properties
of National Institutes for Cultural Heritage, Japan

This letter was written by Saichō (posthumous title Dengyō Daishi; 767–822), the founder of the esoteric Tendai school of Buddhism in Japan. It is addressed to his most beloved disciple, Taihan (b. 778), who was at the time studying at Takaosanji Temple (now Jingoji Temple) in Kyoto with Kūkai (posthumous title Kōbō Daishi; 774–835), the founder of the esoteric Shingon school in Japan. This is the only extant letter in Saichō’s own hand. It is called the Kyūkakujō because it begins with the phrase, “I have not heard from you in a long time” (kyūkaku seion). The letter is written in a form of classical Chinese (kanbun).

On the 23rd day of 11th month of Kōnin 4 (December 19, 813 [Julian calendar]), Saichō wrote a letter to Kūkai asking to borrow the texts Mañjuśrī’s Praises of the Dharma-Body (J. Monju san hosshin rai; Ch. Dasheng wenshushili pusa zan fofashen li), also known as One Hundred and Twenty Lines in Praise of the Buddha together with its accompanying geometric diagrams a nd explanatory notes as well as the Commentary on the Perfection of Wisdom in 150 Lines (J. Shaku rishu kyō ). In response, however, Kūkai heavily criticized Saichō for attempting to study esoteric Buddhism through textual sources alone and refused to lend him the Commentary on the Perfection of Wisdom in 150 Lines. Upon reading this, Saichō wrote Taihan this letter on the 25th day of the 11th month, requesting that Taihan ask Kūkai in person the meaning of Mañjuśrī’s Praises of the Dharma-Body and its accompanying diagrams and notes.

Previous to this, Saichō had received a poem from Kūkai, to which Saichō intended to compose a poem in response. However, the preface of Kūkai’s poem mentioned Mañjuśrī’s Praises of the Dharma-Body and its accompanying diagrams and notes, which Saichō was unfamiliar with. Ever earnest in his dealings, Saichō wanted to read the texts himself in order to write an appropriate poetic response. Even if he was unable to borrow the Commentary on the Perfection of Wisdom in 150 Lines, he at least wanted Taihan to ask about the contents of these other unknown texts.

At this time, Saichō was 47 and Kūkai was 40. In the text of the letter, Saichō takes great care to show respect to Kūkai, despite their age difference, such as always starting a new line when referring to Kūkai and using the honorific title “great teacher.” This careful attention to etiquette reveals the sincerity of Saichō’s character. His calligraphy suggests a high level of sophistication.