四明十義書 1.134

1.134

自有初心便宜修外觀，如先得色無色定，若發心修圓頓止觀，此人已著內心重故，須以外觀破之。於外色等觀成理顯，還將淨色歷一切法及以內心任運泯合也。此如《四念處》唯色唯識二種觀法，被二根機也。

Fourth, there is outer contemplation being expedient for beginners. For instance, if one has previously attained the form and formless dhyānas, when one resolves to cultivate the perfect-sudden cessation and contemplation, because this person's attachment to the inner mind is heavy, one must break it with outer contemplation. When contemplation succeeds on external form and the principle is revealed, one again takes pure form to traverse all dharmas and the inner mind, naturally dissolving and merging with them. This is like the two kinds of contemplation methods in the Si nianchu, form-only and consciousness-only, which accommodate two different faculties.