The anecdote that Yoshitsune and his servants disguised as yamabushi (mountain priests) and headed for Oshu is based on "Azuma Kagami" (The Mirror of the East), "Genpei Seisui ki" (Rise and Fall of the Minamoto and the Taira clans), "Gikeiki" and so forth.
義経主従が山伏に変装して奥州に下向する逸話は『吾妻鏡』、『源平盛衰記』、『義経記』などに拠っている。