Śūraṅgama Sūtra
The "Śūraṅgama Sūtra" is one of the seminal texts of Chán Buddhism. It was first transmitted by Yuquan Shenxiu, the original sixth patriarch and the seminal figure of the Northern school. It "is connected with the enlightenment of" Changshui Zixuan from the Song dynasty and Hanshan Deqing (憨山德清) from the Ming.