The Surangama Sutra describes the methods that twenty-five great bodhisattvas used to attain liberation. These methods of practice include meditations upon the four elements, the six sense faculties, the six categories of sense objects, and six consciousnesses. Using any of these methods, a practitioner can gain liberation. It is the same as what is described in the Heart Sutra. Furthermore, you need not practice all twenty-five methods. One is enough. Like a room with several doors, once you have entered the room, it does not matter which door you used.

For example, Avalokitesvara Bodhisattva contemplated the emptiness of sound. Bodhisattva Universal Vision contemplated the emptiness of the eye. Ksitigarbharaja Bodhisattva contemplated the element of earth, and Sariputra contemplated the emptiness of perception of his mind. In your practice, you can contemplate the nature of a sense faculty, its sense object, or the sense consciousness. The sense faculties and objects are the physical and psychological components inside and outside the body. If you successfully complete your contemplation and wisdom arises, then the practice is realized. The goal is to realize that while the sense faculty, the sense object, and the sense consciousness are empty, they also exist. This is the Mahayana realization: that emptiness and existence are the same. Because everything constantly changes, there is no real existence. Phenomena come, seeming to emerge from emptiness, and return back to emptiness. This is the result of causes and conditions coming together. Proper contemplation is precisely the realization of this emptiness.