摩訶止觀 4.173

4.173

云何欲法界空？外五塵求不可得；內意根求不可得；中間意識求不可得。內外合求不可得；離內外求不可得。過去欲緣求不可得；現在欲因求不可得；未來欲果求不可得。橫竪求之，畢竟寂靜，欲即是空。欲空故，從欲所生一切法亦即是空，空亦不可得。是為觀空棄利鈍蓋也。

How is the dharmadhātu of desire empty? Seeking it in the external five sense-objects, it is ungraspable; seeking it in the internal mental faculty, it is ungraspable; seeking it in the mental consciousness in between, it is ungraspable. Seeking it in the combination of internal and external, it is ungraspable; seeking it apart from internal and external, it is ungraspable. Seeking it in past conditions of desire, it is ungraspable; seeking it in present causes of desire, it is ungraspable; seeking it in future fruits of desire, it is ungraspable. Seeking it horizontally and vertically, it is ultimately quiescent; desire is itself empty. Because desire is empty, all dharmas arising from desire are also empty, and emptiness is also ungraspable. This is contemplating emptiness to discard the sharp and dull hindrances.