肇論新疏 3.203

3.203

經曰「三無為」者，蓋是群生紛繞生乎篤（厚）患，篤患之尤（甚）莫先於有，絕有之稱莫先於無，故借無以明其非有。明其非有，非謂無也。

"When the sutras speak of the 'three unconditioned states,' it is because the confusion and entanglement of sentient beings give rise to grave afflictions. Among the worst of grave afflictions, none comes before existence; among the terms that terminate existence, none comes before non-existence. Therefore, non-existence is borrowed to clarify that it is not existent. Clarifying that it is not existent does not mean that it is non-existent."