What the sūtra is about
The sūtra opens at the Jetavana monastery in Śrāvastī. Ānanda, begging alone, is drawn in by Mātaṅgī through a sorcerer's spell; the Buddha sends Mañjuśrī with a mantra to protect him, and Ānanda returns, regretting that he had valued learning over strength of practice. From his question the Buddha asks seven times where the mind is — inside the body, outside it, behind the eyes… — and shows in turn what is not right in each answer.
Scrolls 2 to 4 turn to the nature of seeing, then show that the six sense bases, twelve spheres, eighteen elements and seven great elements are all the Tathāgatagarbha, neither caused by conditions nor self-existing; Pūrṇa asks how mountains, rivers and earth could arise from a nature pure from the start. In scrolls 5 and 6 the sages tell in turn the «perfect penetration» each practised — Avalokiteśvara speaks of penetration through hearing — and Mañjuśrī is asked which door to choose for beings of later times.
Scroll 7 teaches the four rules of conduct, how to set up a place of practice, and proclaims the mantra; scroll 8 speaks of the twelve kinds of beings, the stages of realisation and the six destinies. The last two scrolls set out the meditation heavens and the māra states that may arise in meditation through the five aggregates of form, feeling, perception, formations and consciousness — the part many people read so as to recognise, and not cling to, unusual states in practice.