摩訶止觀 9.142

9.142

若二法研心而不入者，當知未發真前皆是迷亂。以一心三觀遍破橫竪一切迷亂，迷去慧發，亂息定成。

If grinding the mind with these two dharmas still does not bring entry, one must know that before the true is aroused, all is delusion and disturbance. By using the three contemplations in a single mind, one comprehensively shatters all horizontal and vertical delusions and disturbances; when delusion departs, wisdom arises, and when disturbance ceases, samādhi is accomplished.