Za apitan xin lun 雜阿毘曇心論

Za apitan xin lun 雜阿毘曇心論 (雜阿毗曇心論) "Treatise on the heart of the mind of miscellaneous higher teachings", briefly Zaxinlun 雜心論, is a doctrinal treatise of the Sarvāstivāda School (Ch. Shuo yiqie you bu 說一切有部) of Buddhism. It was composed in India by a person called Dharmatrāta (Chinese transcription [Ct.] Fajiu 法救) and titled Saṃyuktābhidharma-hṛdaya-śāstra. The text was translated into Chinese under the Liu-Song dynasty 劉宋 (420-479) by Saṅghavarman (Ct. Sengjiabamo 僧伽跋摩, 3rd cent.). The work consists of 11 juan (sometimes recorded as 14). Earlier, now lost, translations were produced by during the Eastern Jin 東晉 (317-420) by Saṃghadeva (Ct. Sengjiatipo 僧伽提婆, fl. 383), Faxian 法顯 (337-c. 422), Buddhabhadra (Ct. Fotuobatuolou 佛陀跋陀羅, 359-429), a certain "Yiyeboluo" 伊葉波羅 and Guṇavarman (Ct. Qiunabamo 求那跋摩). These earlier translations are no longer extant.

The Saṃyuktābhidharma-hṛdaya-śāstra was written to explain and supplement the Abhidharma-hṛdaya-(śāstra) (Chinese version called Apitan xin lun 阿毗曇心論), composed by Dharmaśreṣṭhin (Ct. Fasheng 法勝). It is said that the latter was extremely concise, whereas the Mahāvibhāṣā-śāstra (Chinese version Da piposha lun 大毗婆沙論) was overly detailed. Dharmatrāta, therefore, selected useful doctrines from the Da piposha lun, carefully weighing them to find a middle ground, and thus supplemented, organised, and corrected the Apitan xin lun to the Saṃyuktābhidharma-hṛdaya, expanding the original 250 verses to 600.

For certain key doctrines discussed in the Da piposha lun, such as the dvisatya or "Two Truths" (erdi 二諦) and the tryadhva or "Three Ages" (sanshi 三世, i.e., past, present, and future), which could not readily be incorporated into the original text of the Apitan xin lun, an additional chapter called the "Chapter of discrimination" (Ze pin 擇品) was added to elaborate on them. Although the Saṃyuktābhidharma-hṛdaya-śāstra is described as a commentary, it is in fact a restructuring of the Buddhist doctrinal system.

The treatise comprises eleven chapters. Aside from the "Chapter of discrimination", the remaining ten chapters follow the structure of the original Apitan xin lun. Its doctrinal system is centred on the Four Noble Truths (sidi 四諦) as its core framework. In the newly added chapter on Discrimination, the scripture presents several new Sarvāstivāda doctrinal positions, such as "Arhats can regress" (Aluohan you tui 阿羅漢有退), the existence of an intermediate state (antarābhava, zhongxin 中陰), the doctrine that the three ages exist, the gradual realisation of the Four Noble Truths (sidi jianci xianguan 四諦漸次現觀), and the claim that the Buddha is not counted among the saṅgha or monastic community (Fo bu zai seng shu 佛不在僧數). It also interprets the Apitan xin lun statement "that which produces afflictions is defiled (āsrava)" (sheng fannao wei you lou 生煩惱為有漏) by explaining it as "that which increases along with afflictions is defiled" (fannao sui zeng wei you lou 煩惱隨增為有漏).

The Saṃyuktābhidharma-hṛdaya is more complete and substantial because it reconciles the differing views found in the Apitan xin lun and the Da piposha lun, and harmonises various internal doctrinal disagreements within the Sarvāstivāda School. In India, this treatise was once highly influential and significantly impacted the development of Buddhist scholasticism within the Theravada tradition. Vasubandhu (Ct. Shiqin 世親, c. 400 CE) revised the verses of this work by merging, adding, and deleting passages, and reorganised them into a new structure. Based on these revisions, he composed the Abhidharmakośa (Chinese version Jushelun 俱舍論), a critical and synthetic work for the Sarvāstivāda School.

In China, because the Za apitan xin lun was translated multiple times and widely spread, the study of Abhidharma or "higher teachings" (Ct. apitan 阿毗曇 or pitan 毗曇) once flourished for a period, and many scholars dedicated themselves to promoting and studying Abhidharma. They promoted it alongside the Jñāna-prasthāna (Chinese version Fazhilun 發智論) and the Da piposha lun.

Commentaries on the Za apitan xin lun once included Huitong's 慧通 Zaxin yiji 雜心義記, Zhilin's 智林 Pitan zaxin ji 毗曇雜心記, Zhizang's 智藏 (741-819) Apitan yishu 阿毗曇義疏, Zaxin shu 雜心疏 by Jingsong 靖嵩 (537-614) and Zhinian 志念, Daoji's 道基 Zaxin xuanzhang 雜心玄章 and Zaxin chao 雜心鈔, and Huixiu's 慧休 (b. 548) Zaxin xuanzhang chaoshu 雜心玄章鈔疏. All these works are now lost. Only in the Dasheng yizhang 大乘義章, composed by Huiyuan 慧遠 (523–592), certain passages quote or reflect the contents of these earlier commentaries.