摩訶止觀 4.21

4.21

隨定、具足兩戒，即是隨首楞嚴定，不起滅定，現諸威儀，示十法界像，導利眾生。雖威儀起動，而任運常靜，故名「墮定戒」。前來諸戒律儀防止，故名「不具足」；中道之戒無戒不備，故名「具足」。此是持中道第一義諦戒也。用中道慧，遍入諸法，故經云：「式叉。」式叉，名「大乘戒」也。

The two precepts of following concentration and being complete mean following the Śūraṅgama-samādhi: without rising from the cessation-absorption, one manifests all deportments, displays the images of the ten dharmadhātus, and guides and benefits sentient beings. Although deportments arise and move, one is spontaneously and constantly tranquil; hence it is called the 'precept falling into concentration'. The preceding precepts are preventive rules of restraint, and hence are called 'incomplete'; the precept of the middle way lacks no precept, and hence is called 'complete'. This is upholding the precept of the middle way, the supreme ultimate truth. Using the wisdom of the middle way, one ubiquitously enters all phenomena; hence the sūtra says: 'Śikṣā.' Śikṣā means 'the Mahāyāna precepts'.