Ambapālī Sutta (SN 52:9)
I have heard that on one occasion Ven. Anuruddha & Ven. Sāriputta were staying near Vesālī in Ambapālīs forest. Then Ven. Sāriputta, arising from his seclusion in the late afternoon, went to Ven. Anuruddha. On arrival, he exchanged courteous greetings with him. After an exchange of friendly greetings & courtesies, he sat to one side. As he was sitting there, he said to Ven. Anuruddha, “Bright are your faculties, friend Anuruddha; pure your complexion, and clear. By means of what dwelling do you now often dwell?”
“I now often dwell, friend, with a mind well-established in the four establishings of mindfulness. Which four? There is the case where I remain focused on the body in & of itself—ardent, alert, & mindful—subduing greed & distress with reference to the world. I remain focused on feelings in & of themselves… the mind in & of itself… mental qualities in & of themselves—ardent, alert, & mindful—subduing greed & distress with reference to the world.
“I now often dwell, friend, with a mind well-established in these four establishings of mindfulness.
“Any monk whose effluents are ended—who has reached fulfillment, done the task, laid down the burden, attained the true goal, laid to waste the fetter of becoming, and who is released through right gnosis—often dwells with a mind well-established in these four establishings of mindfulness.”
“It is a gain for us, my friend, a great gain for us, that we were right in Ven. Anuruddha’s presence when he said this bull-like statement!”