After the Emperor became a cloistered emperor in the pious life, he found this hoin (a seal used in Temples) in Nakayama-dera Temple of Settsu Province (Takarazuka City, Hyogo Prefecture), where it is said that Tokudo left a hoin (a seal used in temples) inside the stone coffin of the 33 Kannon Reijo (a sacred place) during the early Nara period, the Emperor worked hard and gained the power of the Buddhist dharma (Law) by visiting the 33 Kannon Reijo (a sacred place) from Kumano, Kii Province.
出家し法皇となった後には、奈良時代初期に徳道が観音霊場三十三ヶ所の宝印を石棺に納めたという伝承があった摂津国の中山寺（兵庫県宝塚市）でこの宝印を探し出し、紀伊国熊野から宝印の三十三の観音霊場を巡礼し修行に勤め大きな法力を身につけたという。