Kotsukeijo (the third letter), a reply letter from Kukai dated September 5 of the same year, exhibits that Saicho had asked to lend him scriptures such as "Ninnogyo" (the Sutra of Benevolent Kings).
『忽恵帖』（3通目）は、この年（推定）9月5日付の空海の返書だが、その内容から最澄が『仁王経』などの借用を願い出ていることがわかる。