四明十義書 1.80

1.80

若執真理造如來者，《止觀》不須觀陰顯三千性也。何故不直立真心為境，而立陰等十境耶？何故諸文多以無明心及妄為境耶？故若不即三道而顯三德者，乃教道所說也。

If you hold that true principle creates the Tathāgata, the Zhiguan would have no need to contemplate the aggregates to reveal the nature of the three thousand [realms]. Why did it not directly establish the true mind as the object, but instead established the ten objects such as the aggregates? Why do various texts mostly take the mind of ignorance and delusion as the object? Therefore, failing to reveal the three virtues by being identical to the three paths is an explanation of the teaching path.