四明十義書 1.107

1.107

今據此教文。若內若外、若心若色，趣觀一境皆具三千，以互具互收故也。令著外色者專觀內心，外既歸內，外著則亡。著內心者令專觀外色，內既趣外，內著方祛。外觀本治內著，若還攝外歸內，則彌增內著，重添他病。良可痛哉。

Now, based on this scriptural passage: whether internal or external, whether mind or form, converging in contemplation on a single object, all possess the three thousand, because they mutually possess and mutually include each other. For those attached to external form, one has them contemplate exclusively the internal mind; once the external returns to the internal, external attachment is eliminated. For those attached to the internal mind, one has them contemplate exclusively external form; once the internal converges toward the external, internal attachment is only then dispelled. External contemplation originally cures internal attachment; if one again subsumes the external back into the internal, one will further increase internal attachment and add another illness on top of it. How truly lamentable!