Once when the Venerable Anuruddha and the Venerable Sariputta were living at Vesāli in Ambapālī's Grove. Then, in the early evening, the Venerable Sariputta emerged from his daylong seclusion, went to the Venerable Anuruddha and said: Friend Anuruddha, indeed is your appearance serene and your visual expression is pure & bright! In what dwelling does the Venerable Anuruddha now usually dwell? Now, friend, I usually dwell with a mind well established in the four foundations of awareness. What four? Here, friend, I dwell solely reflecting upon the body only as a formed group ... reflecting upon the feelings only as passing sensations ... reflecting upon the mind only as habitual & transient moods ... reflecting upon all phenomena only as constructed mental states ... while keen, clearly comprehending, acutely aware, thereby removing all desire and frustration rooted in this world. The Bhikkhu, friend, who is an Arahat, one whose mental fermentations are destroyed, who has lived the Noble life, done what had to be done, laid down the burden, reached his own goal, by utterly eliminating the chains of endless re-becoming, one entirely released through final direct knowledge, usually dwells with a mind well established in these four foundations of awareness.... Then Venerable Sariputta exclaimed: It is a gain for us, friend, it is well won by us, friend, that we were in the very presence of the Venerable Anuruddha when he roared such a lion's roar...
Source (edited extract): The Grouped Sayings of the Buddha. Samyutta Nikāya. [V:301-2] section 52: Anuruddha. Thread 9: The All!
