[347] "And how, Ānanda, does a bhikkhu steady the mind (citta) internally, settle it, unify it, and concentrate it? Here, Ānanda, a bhikkhu, quite secluded from sensual pleasures, secluded from unwholesome states, enters and dwells in the first jhāna, which is accompanied by thought and examination, with rapture (pīti) and pleasure born of seclusion … the second jhāna … the third jhāna … the fourth jhāna. It is thus, Ānanda, that a bhikkhu steadies the mind internally, settles it, unifies it, and concentrates it.
He attends to emptiness (suññatā) internally. As he is attending to emptiness internally, his mind does not leap forward into emptiness internally, does not become confident, does not become steady, and does not become resolved. This being so, Ānanda, the bhikkhu understands thus: 'While I am attending to emptiness internally, my mind does not leap forward into emptiness internally, does not become confident, does not become steady, and does not become resolved.' In this way he is clearly comprehending with regard to that.
He attends to emptiness externally. He attends to emptiness internally and externally. He attends to the imperturbable (āneñja). As he is attending to the imperturbable, his mind does not leap forward into the imperturbable, does not become confident, does not become steady, and does not become resolved. This being so, Ānanda, the bhikkhu understands thus: 'While attending to the imperturbable, the mind does not leap forward into the imperturbable, does not become confident, does not become steady, and does not become resolved.' In this way he is clearly comprehending with regard to that.
Then, Ānanda, that bhikkhu should steady the mind internally, settle it, unify it, and concentrate it in that very same previous sign of concentration (samādhinimitta). He attends to emptiness internally. As he is attending to emptiness internally, his mind leaps forward into emptiness internally, becomes confident, becomes steady, and is liberated. This being so, Ānanda, the bhikkhu understands thus: 'While I am attending to emptiness internally, my mind leaps forward into emptiness internally, becomes confident, becomes steady, and is liberated.' In this way he is clearly comprehending with regard to that.
He attends to emptiness externally. He attends to emptiness internally and externally. He attends to the imperturbable. As he is attending to the imperturbable, his mind leaps forward into the imperturbable, becomes confident, becomes steady, and is liberated. This being so, Ānanda, the bhikkhu understands thus: 'While I am attending to the imperturbable, my mind leaps forward into the imperturbable, becomes confident, becomes steady, and is liberated.' In this way he is clearly comprehending with regard to that."
English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.