摩訶止觀 5.83

5.83

《毘婆沙》明三科開合。若迷心，開心為四陰，色為一陰。若迷色，開色為十入及一入少分，心為一意入及法入少分。若俱迷者，開為十八界也。

The Vibhāṣā clarifies the division and combination of the three categories. If one is deluded about mind, mind is opened into four aggregates, and form is one aggregate. If one is deluded about form, form is opened into ten sense fields and a small portion of one sense field, and mind is one mental sense field and a small portion of the dharmāyatana. If one is deluded about both, they are opened into the eighteen realms.