The Dreaming of Poetics 2: from Korai Futeisho

But someone might charge that, whereas in the case of the Mo-ho-chih-kuan it is a matter of transmitting the deep truth by holy men known as the “golden-mothed ones,” what I have brought up for consideration is nothing more than those verbal games known as “floating phrases and fictive utterances” [kyogen-kigo”]. However, quite on the contrary, it is exactly here that the profoundity of things is demonstrated. This is because there exists a reciprocal flow of meaning between such things [as poetry] and the way of Buddhism, a way that maintains the interdependence of all things. This is found in the teaching that:
“Enlightenment is nowhere other than in the worldly passions.”

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Thus, for all these reasons I can now for the record state that the Japanese lyric called the uta has a dimension of depth, one that has affinity with the three stages of truth in Tendai, namely the void [ku], the provisional [ke], and the middle [chu].

from Korai Futeisho by Fujiwara Shunzei, translated by William R. LaFleur in The Karma of Words, p. 90.