梵網經菩薩戒本疏 3.17

3.17

Second, explaining the name: words not matching reality constitute "false" (mṛṣā), and causing another to understand constitutes "speech" (vāda). The precept guards against this lapse, taking its name from what it remedies. The Dazhidulun, fascicle fifteen, states: "False speech means that with an impure mind, wishing to deceive another, concealing the truth, one utters disparate words, generating vocal karma; this is called false speech." Explanation: this also subsumes the other three—harsh speech, divisive speech, and frivolous speech—taking its name from the foremost, because their faults arise mutually. The Dazhidulun states: "Among the four kinds of vocal karma, false speech is the gravest. Furthermore, merely mentioning false speech already subsumes the other three matters. Furthermore, among all dharmas, truth is the greatest. If speech is truthful, the four kinds of right speech are all subsumed."