宗鏡錄 72.21

72.21

答。離開導根。必不轉故。意云。心心所。若不得前念心王為開避引導。即無因得起。

Answer: Because separated from the opening-and-guiding faculty, they definitely do not operate. The meaning is: if mind and mental factors do not obtain the preceding consciousness-king as opening and guidance, they have no cause whereby they may arise.