Sutra of the Three Heaps (ཕུང་པོ་གསུམ་པའི་མདོ་) also known as the The Bodhisattva’s Confession of Downfalls or Confession of Downfalls (Tung Shak), a method of purifying transgressions of vows and downfalls of the bodhisattva vow by invoking thirty-five buddhas of confession.
