瑜伽論記 16.136

16.136

景師等解，憂攝入苦，故云苦根，通緣無色。又解：苦根自證分緣自見分，說緣無色。泰同後說。

Master Jing and others explain: Grief is subsumed under pain, hence it is called the pain faculty, and it generally takes the formless as its cognitive object. Another explanation says: The self-authenticating part of the pain faculty takes its own seeing part as its cognitive object, and so is said to take the formless as its cognitive object. Tai agrees with the latter explanation.