Sokuzan's talk is inspired from verse 26 of the Trimsatika (Thirty Verses) of Vasubandhu on the "Consciousness Only" teachings of the Yogacara:

"As long as consciousness does not see that subject-object distinctions are simply forms of consciousness, attachment to twofold grasping will never cease"

https://www.youtube.com/watch?v=gstDd3ReviI