It is a poem in Gogon Hairitsu (twelve phrases consisting of sixty letters) which was created by Emperor Saga to express his mourning for the death of Saicho in 822, and believed to be the Emperor's shinkan and a copied duplicate rather than his handwritten original document.
弘仁13年（822年）最澄の入寂を悲しんだ嵯峨天皇の五言排律（12句60字）の詩で、宸翰と伝えられるが、自筆原本でなく写しであるとする説もある。