According to the sūtra-mātṛkā (sūtra matrix, 契經, 摩呾理迦 or 本母), essentially a commentary on a portion of the Saṃyukta-āgama, in the Vastusaṅgrahaṇī of the Yogācārabhūmi, the core teachings of the Buddha are these seven topics:
‘Discourses Connected with the Aggregates’
‘Discourses Connected with the Sense Spheres’
‘Discourses Connected with Causal Condition’
‘Discourses Connected with the Nutriments’
‘Discourses Connected with the Truths’
‘Discourses Connected with the Elements’
‘Discourses Connected with the Path: the Stations of Mindfulness, etc., of the Enlightenment Factors’
These seven topics (without the sections spoken by Śrāvakas and the Tathāgata) are considered by Ven. YinShun to be the most fundamental and earliest portion of the ‘Connected Discourses’ (相應教, saṃyukta-kathā) of the Saṃyukta-āgama. They are found in the five major sections (varga) on aggregates, sense spheres, causal condition (including nutriments, truths and the elements) and path of the extant Saṃyukta-āgama/Saṃyutta-nikāya.