Turning the Light Back to Observe the Nature of Hearing, Not Falling into Sounds

The practice of deepening through a single gate among the eighteen dhātus means contemplating one of the eighteen dhātus, awakening to the true reality of the dharmadhātu through that one dhātu, and attaining samādhi, thereby opening great wisdom. For example, if one cultivates through the gate of the ear faculty, one must engage in contemplative practice (vipaśyanā-caryā) upon the nature of hearing, introspectively observing the place of arising and ceasing of the ear faculty's nature of hearing, and thereby find the true, unarising-and-unceasing nature of hearing. At this time, one must not fall into sounds and go on to deliberate about the content within sounds; only in this way can one find the root and essence of the nature of hearing.