In Rusui choja (sresthin "Flowing Water") chapter of the "Konkomyo-kyo Sutra" (Golden Light Sutra), there is a Jataka tale (Buddhist Tale) that tells how when Sakyamuni Buddha's previous incarnation, Rusui choja, helped countless fish that faced death when a large lake dried up and released them to safety, the fish were reincarnated into the Heaven of the Thirty-three Celestials and repaid Rusui choja for his kindness.
『金光明経』長者子流水品には、釈迦仏の三世であった流水（るすい）長者が、大きな池で水が涸渇して死にかけた無数の魚たちを助けて説法をして放生したところ、魚たちは三十三天に転生して流水長者に感謝報恩したというジャータカが説かれている。