A bodhisattva should follow, expand and fulfill this liberating practice; he or she should resolve to enter the calm bliss of Nirvana, asking himself or herself: Who am I, and what is my object? How do I obtain Bodhi? By means of the body or by means of the mind? If ‘body’ is my answer, then how is it done? This body is as obstinate and as unaware as grass, wood, stone, or as a wall; or like a reflection in the mirror. The Bodhi is formless, imperceptible and beyond attachment. How am I to obtain subtle, supramundane Bodhi with a body that is so obstinate, so unaware? If I answer that the mind is a means to attain Bodhi, then how should I manage this mind which, like the Bodhi, has no form? Mind is identical with delusion and cannot be known. How can I reach it, in what direction? How can I attain Bodhi and how do I know when I have attained it? The meditator should ponder in this manner, until he or she understands clearly that neither the body nor the mind are the Bodhi…Observing in this manner, one can easily enter samadhi of complete extinction or non-discrimination of dharmas, and perceive all dharmas as void.
The Teaching for Bhadrapala Sutra
If you practice what I just taught you, you will attain true samadhi: Not discriminating while observing the body or any of its parts is what all dharmas teach. Bodhisattvas should observe in this manner, in accordance with the Fourfold Base of Mindfulness. Likewise, while observing one’s mind, one should observe discrimination as one of its forms; in the same way, discrimination should be noticed while one is observing dharmas, and once observed, it should be abandoned. Bodhisattvas should practice in this manner while they seek to develop the concentration leading to the attainment of samadhi. When a bodhisattva observes form, perception or mind without discrimination, he or she will understand that, ultimately, there are no dharmas to be obtained. How or where could discrimination arise? All dharmas are, therefore, void of discrimination. Because of non-discrimination there is no thought, and in its absence no dharmas can perceived. Without dharmas there can be no obstacles, and when there are no obstacles, samadhi is attained. When that happens, the bodhisattva perceives myriads of oceanic buddha-fields manifesting themselves as countless buddhas, and hears untold dharmas completely without obstacles. It is the supreme liberation or nirvana, it is the attainment of an unobstructed knowledge. Again, Bhadrapala, when a bodhisattva observes according to the Fourfold Base of Mindfulness, eventually there are no dharmas to be perceived or thought of, and for that reason there can be no discrimination whatsoever.
The Teaching for Bhadrapala Sutra