南宗頓教最上大乘摩訶般若波羅蜜經六祖惠能大師於韶州大梵寺施法壇經 1.25

1.25

「今既如是，此法門中，何名坐禪？此法門中，一切無礙，外於一切境界上念不起為坐，見本性不亂為禪。何名為禪定？外離相曰禪，內不亂曰定。外若離相，內性不亂。本性自淨曰定，只緣境觸，觸即亂，離相不亂即定。外離相即禪，內不亂即定，外禪內定，故名禪定。《維摩經》云：『即時豁然，還得本心。』《梵網菩薩戒經》云：『本源自性清淨。』善知識！見自性自淨，自修自作自性法身，自行佛行，自作自成佛道。

"Now that this is so, in this Dharma door, what is called sitting in meditation? In this Dharma door, everything is unobstructed: outwardly, not having thoughts arise toward any sensory realm is sitting; seeing the original nature without disturbance is meditation. What is called dhyāna-samādhi? Outwardly being detached from forms is called dhyāna; inwardly being undisturbed is called samādhi. If one is outwardly detached from forms, the inner nature will not be disturbed. The original nature being naturally pure is called samādhi; it is only because of contact with realms that contact brings disturbance, and detachment from forms without disturbance is samādhi. Outwardly being detached from forms is dhyāna; inwardly being undisturbed is samādhi. Outward dhyāna and inward samādhi—therefore it is called dhyāna-samādhi. The Vimalakīrti Sūtra says: 'Suddenly and completely, one regains one's original mind.' The Brahmā Net Bodhisattva Precept Sūtra says: 'The original source of one's own-nature is pure.' Kalyāṇamitras! See that your own-nature is inherently pure; cultivate yourself and make your own-nature dharmakāya; practice the Buddha's conduct yourself, and accomplish the Buddha Way yourself."