摩訶止觀 6.117

6.117

或四法為藥，謂四念處。諸見皆依色，此色非污穢、非不污穢；受諸見思非苦、非樂；諸見想行非我、非無我；諸見思心尚非心，豈是常、無常？

Or four dharmas are taken as medicine, namely the four smṛtyupasthānas: all views rely on form, but this form is neither defiled nor non-defiled; receiving all views and thoughts is neither suffering nor pleasure; the conceptions and formations of all views are neither self nor non-self; the mind of all views and thoughts is not even mind, how could it be permanent or impermanent?