Ven. Yin Shun in his book (CSA vol. 1) states that Samyukta-agama is the foundation of both the four agamas/nikayas and Mahayana Madhyamaka and Yogācāra's essential teachings:
"《雜阿含經》（即《相應阿含》，《相應部》），是佛教界早期結集的聖典，代表了釋尊在世時期的佛法實態。佛法是簡要的，平實中正的，以修行為主，依世間而覺悟世間，實現出世的理想——涅槃。在流傳世間的佛教聖典中，這是教法的根源，後來的部派分化，甚至大乘「中觀」與「瑜伽」的深義，都可以從本經而發見其淵源。這應該是每一位修學佛法者所應該閱讀探究的聖典。
... 其實，四部阿含是先有《雜阿含》，九分教是先有「修多羅」，「祇夜」，「記說」（這三分也還是先後集出），二者互相關聯，同時發展而次第成立的。《中阿含經》（[A1]一九一）《大空經》，說到「正經，歌詠，記說」（《中部》一一二《空大經》所說相同），正是佛教初期三分教時代的明證。
《瑜伽論．攝事分》中，抉擇契經宗要的摩呾理迦，是《雜阿含經》的部分論義，也就是「所說」——「修多羅」部分的論義。「修多羅」分陰、處、因緣、聖道四大類，在《雜阿含經》的集成中，「修多羅」是最早的，正是如來教法的根本所在。"
See also Choong Mun-keat:
“Ācāriya Buddhaghosa and Master Yinshun 印順 on the Three-aṅga Structure of Early Buddhist Texts” in Research on the Saṃyukta-āgama (Dharma Drum Institute of Liberal Arts, Research Series 8; edited by Dhammadinnā), Taiwan: Dharma Drum Corporation, August 2020, pp. 883-932.
ttps://www.academia.edu/44055729/%C4%8 ... hist_Texts
The Fundamental Teachings of Early Buddhism: A Comparative Study Based on the Sūtrāṅga portion of the Pāli Saṃyutta-Nikāya and the Chinese Saṃyuktāgama (Series: Beitrage zur Indologie Band 32; Harrassowitz Verlag, Wiesbaden, 2000), pp. 7-11.
https://www.academia.edu/39352226/The_F ... ukta_agama
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What do you think regarding the findings of Ven. Yin Shun, particularly Mahayana Madhyamaka and Yogācāra's essential teachings are found in Samyukta-agama?
Mahayana Buddhism and Samyukta-agama
Re: Mahayana Buddhism and Samyukta-agama
I think the essential teachings of Mādhyamika tradition, such as the middle way of emptiness in the expressions of
neither existence (arising) nor non-existence (ceasing), neither eternalism nor annihilationism, neither sameness nor difference neither coming nor going (不生亦不滅, 不常亦不斷, 不一亦不異, 不來亦不出; anirodham anutpādam anucchedam aśāśvatam/anekārtham anānārtham anāgamam anirgamam), are certainly found in Samyukta-agama.
See pp. 32-42 in Choong Mun-keat's The Notion of Emptiness in Early Buddhism https://www.academia.edu/38943344/The_N ... y_Buddhism
neither existence (arising) nor non-existence (ceasing), neither eternalism nor annihilationism, neither sameness nor difference neither coming nor going (不生亦不滅, 不常亦不斷, 不一亦不異, 不來亦不出; anirodham anutpādam anucchedam aśāśvatam/anekārtham anānārtham anāgamam anirgamam), are certainly found in Samyukta-agama.
See pp. 32-42 in Choong Mun-keat's The Notion of Emptiness in Early Buddhism https://www.academia.edu/38943344/The_N ... y_Buddhism