According to legend, Roben confined himself to Senju-kutsu Cave (literally, cave of thousand hands) where he prayed, an act which is said to have removed the rocks on the bed of the Kizu-gawa River that were preventing the passage of cargo ships.
伝承によれば、良弁は笠置山の千手窟に籠って修法を行い、その功徳によって木津川の舟運のさまたげとなっていた河床の岩を掘削することができたという。