Zhong ahan jing 中阿含經

Zhong ahan jing 中阿含經 "Sutra of Middle-[Length] Sermons" is a key scripture of early Buddhism. It is one of the four Āgamas (Chinese transcription [Ct.] ahan 阿含) or "collections of discourses" in the "Northern" or Mahāyāna tradition. Its name comes from the individual sutras (sermons) it includes, which are of moderate length. It was translated from the Sanskrit original Madhyamāgama-sūtra during the Eastern Jin period 東晉 (317-420) by Saṃghadeva (Ct. Sengjiatipo 僧伽提婆) and Saṃgharakṣa (Ct. Sengjialuocha 僧伽羅叉), in a version of sixty juan. According to tradition, Dharmanandi (Ct. Tanmonanti 曇摩難提) translated fifty-nine fascicles in the Former Qin empire 前秦 (351-394), but this early translation is now lost.

This sutra was transmitted by the Sarvāstivāda School (Ch. Shuo yiqieyou bu 說一切有部). Its original Sanskrit text no longer survives; however, fragmentary Sanskrit manuscripts have been discovered in Xinjiang. Over the centuries, numerous independent sermons from the entire scriptural corpus have also been translated; according to the book catalogue Jingke Dazangjing mulu 精刻大藏經目錄 (1945), seventy-three separate editions are extant today.

The Chinese version of the Zhong ahan jing broadly corresponds to the Majjhima-nikāya in the Pali Canon, although the Chinese collection includes more sutras or sermons. It is generally believed that before the compilation of the Chinese Zhong ahan jing and the Majjhima-nikāya in Pali language, many of the sutras were already circulating individually. In both the "Northern" and "Southern" (Theravada) textual traditions, the sutras are not arranged in the order in which they were originally composed.

The Zhong ahan jing contains 222 sermons, divided into five recitation groups (Sa. saṃyukta, Ch. wusong 五誦) and eighteen sections (Sa. pīṭhas, Ch. pin 品). Their arrangement is as follows: The "Karma Saṃyukta" (Ye xiangxing pin 業相應品) contains ten sutras that primarily expound doctrines of karmic retribution and rebirth (yingbao lunhui 業報輪回), while also refuting the ascetic and karma-denying views of the Jain and other heterodox schools. The "Unprecedented Dharmas Saṃyukta" (Wei zeng you fa pin 未曾有法品) contains ten sutras mainly recording the Buddha's past lives and the monastic discipline and practices of his disciples, such as Ānanda (Ct. Anan 阿難). Similarly, sections like the "Fundamental Differentiation Saṃyukta" (Genben fenbie pin 根本分別品) gather sutras that discuss the same doctrine into a single section. The Śāriputra Saṃyukta (Shelzi xiangying pin 舍利子相應品) contains eleven sutras, all narratively related to Śāriputra, a trusted disciple of the Buddha. The chapter "On sets of seven" (Qifa pin 七法品) contains ten sutras, each of which uses seven illustrative similes to expound the teaching. Other saṃyuktas are titled according to a central sermon, such as the "Longevity King Saṃyukta" (Changshou Wang pin 長壽王品) and the "Puḷido Saṃyukta" (Fuliduo pin 脯利多品). Additionally, there exists a section called the "Double Saṃyukta" (Shuangpin 雙品). In this section, the first five sutras are placed in the fourth recitation group, and the remaining five in the fifth recitation group, hence the name "Double".

The sutra collection offers detailed explanations of the interrelationships among various practices and their role in attaining nirvāṇa and liberation. It provides an extensive discussion of the relationship among the three trainings (sanxue 三學: Sa. śīla/Ch. jie 戒, samādhi/ding 定, and prajñā/hui 慧) and their connection to nirvāṇa. The text also explains how to eradicate avidyā or ignorance (wuming 無明), how spiritual practice generates merit, and the stages of cultivation leading to liberation. It elucidates the application to social reality, illustrating karmic cause and effect and encouraging householders and laypeople to abandon evil deeds and practise virtue. It presents an exposition of early Buddhist doctrines, including the Four Noble Truths (sidi 四諦), the Noble Eightfold Path (bazheng dao 八正道), dependent origination (yuanqi 緣起), the Twelve Links of Dependent Origination (shi'er yinyuan 十二因緣), the Four Meditative Absorptions (sichan 四禪), the six realms of existence (liujie 六界), the six sense bases (liuchu六處), and the eighteen mental factors (caitasikas, shiba yixing 十八意行). These sections emphasise anitya or impermanence (wuchang 無常), anātman or non-self (wuwo 無我), and the universality of suffering (yiqie jie ku 一切皆苦). Most sections focus on specific doctrinal issues and use examples from daily life or allegorical stories to illustrate the teachings.

The sutra is especially notable for emphasising the connections between various teachings. Many later sutras and vinaya texts regularly cite its content.