For over a thousand years, the Śūraṅgama Sūtra — the “Sūtra of the Indestructible”— has been held in great esteem in the Mahāyāna Buddhist countries of East and Southeast Asia. In China the Sūtra has generally been considered as important, and has been as popular as the Lotus Sūtra, the Avataṁsaka Sūtra, the Mahāyāna Mahāparinirvāṇa Sūtra, the Heart Sūtra, and the Diamond Sūtra. The appeal of the Śūraṅgama Sūtra lies in the broad scope of its teachings and in the depth and clarity of its prescriptions for contemplative practice. Its wealth of theoretical and practical instruction in the spiritual life often made it the first major text to be studied by newly ordained monks, particularly in the Chan School. Many enlightened masters and illustrious monastic scholars have written exegetical commentaries on it. To this day, for both clergy and laity in the Chinese Buddhist tradition, the Śūraṅgama Sūtra continues to be the object of devout study, recitation, and memorization.
More specifically, the Śūraṅgama Sūtra has traditionally been regarded as a complete and practical manual for spiritual practice that will eventually lead to enlightenment. It gives instruction in the correct understanding of the Buddha-nature, which is the potential within all beings for becoming a Buddha. The Sūtra explains how and why this true nature is hidden within our ordinary experience of ourselves and of the world, and it shows how we can uncover this nature and recognize that it is our own true mind. The Sūtra also explains that personal integrity and purity of conduct are essential prerequisites for spiritual awakening. It presents the general principles of Buddhist meditation, introduces several specific meditation methods, and recommends which methods are the most effective and the easiest to practice. Further, a considerable portion of the Sūtra is devoted to guidelines for discerning what understandings and practices are correct and which deviate into wrong ones. It explains how our own intentional acts, whether physical, verbal, or mental, directly result in our experiences, including our future rebirths at various levels of being, both human and non-human. It shows how correct action can also lead to initial awakenings and eventually to the perfect enlightenment of the Buddhas.
Much of the Sūtra is devoted to the Buddha Śākyamuni’s instructions to the young monk Ānanda, whose personal story provides a narrative frame for the entire discourse. Joined by several of his enlightened disciples, the Buddha, shows Ānanda how to turn the attention of his sense-faculties inward in order to achieve a deeply focused state of meditation known as samādhi. He tells Ānanda that by practicing a particular form of samādhi, the Śūraṅgama Samādhi, he and anyone else who also maintains purity of conduct and develops right understanding can gain an awakening that is identical to the minds of all Buddhas.
At the heart of the Sūtra is the Śūraṅgama Mantra. The Sūtra promises that the practice of reciting this mantra, in the context of the other practices taught in the Sūtra, can succeed in eliminating whatever internal or external obstacles may lie in the way of spiritual progress. To this day, monks and nuns in the Chinese Buddhist tradition, as well as many practitioners among the laity, recite the mantra every morning as an essential aspect of daily practice.