Saṃyuktāgama (294), Part 1

At that time, the World-Honored One addressed the bhikkhus: "Ignorant, uninstructed ordinary beings, obscured by ignorance and bound by the fetter of craving, obtain this consciousness-body. Internally, there is this consciousness-body; externally, there are name-and-form. These two conditions give rise to contact. Contacted by these six sense-spheres of contact, ignorant, uninstructed ordinary beings feel pleasant, painful, or neutral sensations. Based on these, various [mental formations] arise. What are the six? The sense-sphere of eye-contact, the sense-sphere of ear-contact, nose-contact, tongue-contact, body-contact, and the sense-sphere of mind-contact."

Explanation: The World-Honored One said to the bhikkhus: Ignorant, uninstructed ordinary beings, because they are obscured by the covering of ignorance and bound by the fetter of craving, have their six consciousness-bodies fettered. Internally, there is this sixfold consciousness-body; externally, there is the fivefold name-and-form aggregate. When these internal and external sixfold bases (āyatana) combine, contact arises. After contact arises at the six sense-spheres of contact, ignorant, uninstructed ordinary beings give rise to feelings of pleasant, painful, and neutral sensations. Because there are sensations, they subsequently give rise to craving, grasping, and other causes and conditions for birth and death, causing the cycle of birth and death to continue unceasingly. What are the six sense-spheres of contact? They are the sense-sphere of eye-contact, ear-contact, nose-contact, tongue-contact, body-contact, and mind-contact.

The minds of sentient beings are all obscured by ignorance. If ignorance is removed, clarity shines forth from the mind, and all principles and phenomena become completely clear. The Buddha's mind has no obscuration; his mind radiates light, illuminating heaven and earth, making the entire ten-direction Dharma-realm utterly bright. Every ordinary being has the fetter of craving binding them internally, thus there is the eye-consciousness-body, ear-consciousness-body, nose-consciousness-body, tongue-consciousness-body, body-consciousness-body, and mind-consciousness-body. These six consciousness-bodies are called the consciousness-body. Without craving, there would be no such consciousness-bodies. Having the six consciousness-bodies, they contact the eleven types of material phenomena (rūpa) and mental phenomena (nāma), giving rise to pleasant, painful, and neutral sensations.

Due to craving accumulated over beginningless kalpas, sentient beings have this sixfold consciousness-body. Why are the six consciousnesses considered internal? Because they are produced within the superior root-faculty (indriya). Why is name-and-form considered external? Because name-and-form is an external input; it enters from outside the superior root-faculty and contacts the six consciousnesses, giving rise to sensations. After that, bodily, verbal, and mental formations continue unceasingly, and the six consciousnesses persist without cessation. When the six sense faculties do not contact the six sense objects, the six consciousnesses cease. When the six consciousnesses cease, there is no arising of various phenomena; nothing whatsoever exists. At this point, we gain clarity regarding this chain of the twelve links of dependent origination. All activities of the five aggregates become clear. If bodily, verbal, and mental formations do not cease, the six consciousnesses will inevitably continue to arise. The mind always grasps and clings, so the six consciousnesses are constantly compelled to arise and serve you. As long as the conscious mind does not cease, there is the future life; this is the cause for the next life.