四明十義書 1.108

1.108

又上人堅破，若修內觀恐心外向，所修外觀恐心內向。以為內外相隔非是圓融，則有彼彼草木各一佛性之過也。意謂修內觀時既具三千，三千便是外境，則外諸事境一時遍觀方為圓觀也。皆由上人不諳內外二境不分而分，故妄有破斥也。

Furthermore, you, Venerable Sir, stubbornly refute this, arguing that if one cultivates internal contemplation, one fears the mind will tend outward, and if one cultivates external contemplation, one fears the mind will tend inward. Considering that the separation between internal and external is not perfect fusion, there would be the fault that each and every plant and tree has its own distinct Buddha-nature. Your idea is that when cultivating internal contemplation, since it possesses the three thousand, and the three thousand are external objects, then all external phenomenal objects must be contemplated everywhere at once to be the perfect contemplation. This is all because you, Venerable Sir, do not understand that the internal and external objects are divided without being divided, and thus you make wild refutations.