The Āgama Oral Explanation Sūtra on the Twelve Links of Dependent Origination

(2) Original text: The cycle of birth and death for humans arises from the internal twelve links of dependent origination. The birth and death of all phenomena arise from the external twelve links. What is ignorance (avidyā)? It means not revering one's parents, failing to distinguish right from wrong. From this condition of ignorance arises clinging (upādāna). One does not wish to abandon it, nor does one believe in the present life or the afterlife. Having begun virtuous deeds, one then ceases them due to ignorance. Therefore, one does not attain the good result. Thus, when there is ignorance, there is volitional formation (saṃskāra). When there is volitional formation, there is consciousness (vijñāna). When there is consciousness, there is name-and-form (nāmarūpa). When there is name-and-form, there are the six sense-spheres (ṣaḍāyatana). When there are the six sense-spheres, there is contact (sparśa). When there is contact, there is sensation (vedanā). When there is sensation, there is craving (tṛṣṇā). When there is craving, there is clinging (upādāna). When there is clinging, there is becoming (bhava). When there is becoming, there is birth (jāti). When there is birth, there is aging-and-death (jarāmaraṇa). 

Explanation: Human birth and death arise from the internal twelve links of dependent origination, while the arising and ceasing of phenomena arise from the external twelve links. What is ignorance? Ignorance is not revering one's parents and failing to distinguish right from wrong. From the condition of ignorance arises clinging, yet one cannot abandon this ignorance. One does not believe in the present life nor in the future life. Having already begun virtuous deeds, one then ceases them due to ignorance, and thus fails to attain the good result. Therefore, it is said that when there is ignorance, there is volitional formation. When there is volitional formation, the six consciousnesses arise. When there is consciousness, future name-and-form arises. When there is name-and-form, the six sense-spheres arise. When there are the six sense-spheres, contact arises. When there is contact, sensation arises. When there is sensation, craving arises. When there is craving, clinging arises. When there is clinging, the becoming for the next life arises. When there is becoming, birth arises. When there is birth, aging and death arise. 

Original text: Therefore, after birth, humans grasp the twelve links of dependent origination. It is through the twelve links that birth occurs. Without conditions, not only do humans not arise, but all phenomena also do not arise. If one does not sever the twelve links, one cannot escape the cycle of birth and death. Cultivating the thirty-seven factors of enlightenment is for the purpose of attaining the Way from this. The twelve links of dependent origination consist of five categories. The first is ignorance (avidyā). The second is karmic formations perpetuating birth and death (saṃskāra). These two are the causal conditions from past lives. The third is consciousness (vijñāna). From consciousness, the body is born. The fourth is name-and-form (nāmarūpa). The physical body further develops into the five aggregates (skandhas). These are the causal conditions for the present life. The fifth is the six sense-spheres (ṣaḍāyatana). They again plant the seeds for karmic formations perpetuating birth and death. These are the causal conditions for future lives. Because the twelve links revolve through the past, present, and future lifetimes as mutually conditioning causes, they are summarized into these five categories. 

Explanation: Therefore, after birth, humans grasp the twelve links of dependent origination. It is through the law of the twelve links that humans are born. Without conditions, not only would humans not arise, but all phenomena would also not arise. If one does not cut off the twelve links, one cannot be liberated from the cycle of birth and death. Cultivating the thirty-seven factors of enlightenment is for the purpose of realizing the fruit of the Way and escaping birth and death. The twelve links of dependent origination are divided into five categories: The first is ignorance. The second is volitional formations perpetuating birth and death (karmic formations). These two are the causal conditions from past lives, enabling the continuous arising of future lives, hence the birth and death of the present five aggregates. The third is the six consciousnesses. From the karmic seeds within the six consciousnesses, the physical body is born. The fourth is name-and-form, which allows the physical body to develop the functions of the five aggregates. This is the causal condition for the existence of the five-aggregate body in the present life. The fifth is the six sense-spheres, which diligently plant the seeds of karmic formations and are the causal condition for the birth of the physical body in future lives. The twelve links of dependent origination are the causal conditions for birth and death revolving through the past, present, and future lifetimes, summarized into these five categories.