梵網經菩薩戒本疏 3.40

3.40

Second, explaining the name: The precept against speaking of the sinful offenses of lay and monastic bodhisattvas, monks, and nuns. Now, since their station is yet inadequate, who is free from mistakes? Hence it is called "sinful offenses." Announcing and relating them contrary to principle is therefore called "speaking." Guarding against these karmic wrongs is therefore called "precept." Thus, the words are named after what is spoken, and the precept takes its designation from what is guarded against; both are determinative compounds (tatpuruṣa). Also, speaking of the shortcomings and merits of the Three Jewels is as stated in the sūtra.