梵網經古迹記 1.128

1.128

述曰：第二、慧行。謂內空等，如《辨中邊》、《智論》廣說。於此第十泯第九也。總結十空性平等地，可以十門假說而不著故，亦不可說。

The commentary says: Second, the practice of wisdom. This refers to internal emptiness and so forth, as explained at length in the Madhyāntavibhāga and the Mahāprajñāpāramitopadeśa. In this tenth, the ninth is dissolved. Concluding the ground of the equality of the ten natures of emptiness, one can provisionally speak of it through ten gates without attachment, hence it is also inexpressible.