During the Sung Dynasty, Ch’an’s basic elements as defined by the T’ang Dynasty masters continued and evolved. The great innovation in Sung Dynasty Ch’an is the sangha-case collection. The Ch’an written tradition is composed primarily of prose works by and about Ch’an masters, records of their lives and teachings. These records contain a great deal of conventional explanatory teaching, which is necessary to prepare students for Ch’an’s wordless insight. That direct insight is conveyed in the more literary dimension of those records: poetry, which was perfectly suited to the quick, deep insights of Ch’an, and story-telling typified by poetic distillation: enigmatic sayings and wild antics intended to upend reason and tease mind past the limitations of logical thought. These are performative, rather than explanatory—enacting insight rather than talking about it. As such, they operate with poetic wildness and immediacy, rather than the usual explanatory or utilitarian discourse. In this, they come as close as language can to Ch’an’s transmission outside of words and teaching.