The Jindan sibai zi, or Four Hundred Words on the Golden Elixir, is attributed to Zhang Boduan, the well-known author of the Wuzhen pian (Awakening to Reality). The text is made of twenty poems, each containing four verses of five Chinese characters. It is translated here with the commentary by Peng Haogu (fl. 1586–99). His work is one of many examples showing that commentaries to Neidan texts not only offer explications of the original texts, but are Neidan works to all effects.