妙法蓮華經玄義 6.127

6.127

二、約言辭者，如佛得道夜至泥洹夕，常說般若，常說中道，而一音演法，隨類異解。一音巧說，是則為妙；異類殊解，自有麁妙。

Second, in terms of words: from the night the Buddha attained the Way to the evening of parinirvāṇa, he constantly expounded prajñā and constantly expounded the Middle Way; yet through a single sound he proclaimed the Dharma, and each type [of being] understood it differently according to its kind. The skillful exposition in a single sound is subtle; the distinct understandings of the diverse kinds naturally have their crude and subtle.