翻譯名義集 4.116

4.116

【三跋羅】此翻護，即是無表思，第六識相應善思也。又名無表色，有止惡防非功能，故云護。故《金剛鈔》明戒體，克出體性，即無表思一法也。

[Saṃvara] Here translated as "restraint" (護). This is non-informative volition (avijñapti-cetanā), wholesome volition associated with the sixth consciousness. It is also called non-informative form (avijñapti-rūpa). Because it has the capacity to stop evil and prevent wrong, it is called restraint. Therefore, when the Diamond Subcommentary clarifies the essence of the precepts, singling out their substantial nature, it is precisely this single dharma of non-informative volition.