摩訶止觀 5.187

5.187

佛自釋六句：「云何不生生不可說？不生名為生，故不可說。」今解：「不生」者，法性也；「生」者，無明也。二乘證不生，猶受法性生，故言「不生名為生」。依佛此旨，知是界外附體之惑，不生而名為生。生即顛倒，顛倒即不顛倒；心行處滅，言語道斷，故不可說。

The Buddha himself explains the six phrases: "Why is non-arising arising ineffable? Non-arising is called arising; therefore it is ineffable." It is now explained: "non-arising" is dharmatā; "arising" is avidyā. Practitioners of the two vehicles realize non-arising, yet still receive birth in dharmatā; hence it says "non-arising is called arising." Relying on this intention of the Buddha, we know this refers to the afflictions outside the realms that adhere to the essence: not arising, yet called arising. Arising is inversion; inversion is non-inversion. The locus of mental activity is extinguished, and the path of speech is cut off; therefore it is ineffable.