Touzi Yiqing is a significant figure in the lineage of
Caodong Chan/
Sōtō Zen because he did not actually study under the man commonly regarded as his predecessor, namely
Dayang Jingxuan. This is a unique exception to an otherwise steadfast rule that a lineage must involve direct teacher-to-student
dharma transmission in order to be considered valid. Juefan Huihong's biographical compilation of 1119, the
Chanlin sengbao zhuan (Chronicle of the Sangha Treasure in the Groves of Chan), claims that Touzi Yiqing was the "true son" of Dayang Jingxuan. The
Xudeng lu of 1101 lists Touzi and nine others as disciples of Dayang. However, it also explains that Touzi did not actually ever meet Dayang, let alone receive dharma transmission from him. Instead, Touzi received dharma transmission from
Fushan Fayuan, who had been a student of Dayang, but had himself had not received dharma transmission from Dayang either. In fact, Fushan had already received dharma transmission in the
Linji tradition, and thus could not receive it again. The scholar Morten Schlütter notes that this form of lineage transfer "has no real parallel in early Chan literature". This refers to the fact that Touzi was able to be considered the immediate heir to Dayang's lineage without having met him, and that Fayuan was able to hold Dayang's lineage "in trust" without actually being a bona fide heir. Schlütter further interprets Huihong's likely embellished account as an attempt to strengthen the rather weak link between Touzi and Dayang, who was the last Caodong monk recorded in the prestigious
Transmission of the Lamp, in order to solidify the legitimacy of the lineage. ==References==