A group of three suttas. Sāriputta and Moggallāna go to Anuruddha and ask him various questions. Anuruddha says that the four satipatthānas should be attained both by the sekha and the asekha (the learner and the adept), and declares that he himself came to understand the thousand-fold world-system by developing these four. S.v.298f.