These sources contained numerous stories of famous past Chan masters which were used to educate Chan/Zen students. According to Morten Schlütter "it is not clear exactly when the practice of commenting on old gongan cases started, but the earliest Chan masters to have such commentaries included in the recorded sayings attributed to them appear to be Yunmen Wenyan and Fenyang Shanzhao (947-1024)."

According to Robert Buswell,