祕藏宝钥 (祕藏寶鑰) mì cáng bǎo yào

mì cáng bǎo yào proper noun Hizō Hōyaku; The Precious Key to the Secret Treasury
Domain: Buddhism 佛教 , Subdomain: Japan , Concept: Canonical Text 典籍
Notes: Text by Japanese monastic Kūkai (Ding '秘藏寶鑰'; FGDB '祕藏寶鑰'; Hakeda 1972, pp. 157-224; Wikipedia 'Kūkai')