When he paid a homage to Rakan-ji Temple, Bungo Province (today's Nakatsu City) during his pilgrimage, he learned that Aono-watari, a pier built on a cliff along a river, was so fragile and shaky that people and horses often fell down into the river and felt so sorry that he made a vow of building a path and came up with the idea of excavating for the path.
回国の途中、豊後国羅漢寺(中津市)を参詣した時、川沿いの断崖にかけられた桟橋、青野渡が危険で、人馬のしばしば覆没することを知り、これを哀れみ、鑿道の誓願を発し、陸道の掘削を思いついた。