In addition, the details of the step-up from the Zen meditation practice done by ordinary persons and a believer of a religion other than Buddhism, to the Zen practice reaching the same status as Buddha with the holy wisdom lead by ones own power, are shown in "Tetsugan-zenji Kana Hogo" (Zen-master Tetsugan's Explanation of the teachings of Buddha in kana).
また、愚夫所行禅から如来清浄禅に至るまでの上達の様子については『鉄眼禅師仮字法語』に詳しい。