Catutthajhānapañhāsutta
“‘Catutthaṁ jhānaṁ, catutthaṁ jhānan’ti vuccati. Katamaṁ nu kho catutthaṁ jhānanti? Tassa mayhaṁ, āvuso, etadahosi: ‘idha bhikkhu sukhassa ca pahānā dukkhassa ca pahānā pubbeva somanassadomanassānaṁ atthaṅgamā adukkhamasukhaṁ upekkhāsatipārisuddhiṁ catutthaṁ jhānaṁ upasampajja viharati. Idaṁ vuccati catutthaṁ jhānan’ti. So khvāhaṁ, āvuso, sukhassa ca pahānā dukkhassa ca pahānā pubbeva somanassadomanassānaṁ atthaṅgamā adukkhamasukhaṁ upekkhāsatipārisuddhiṁ catutthaṁ jhānaṁ upasampajja viharāmi. Tassa mayhaṁ, āvuso, iminā vihārena viharato sukhasahagatā saññāmanasikārā samudācaranti.
A Question About the Fourth Absorption
“They speak of this thing called the ‘fourth absorption’. What is the fourth absorption? It occurred to me: ‘It’s when, with the giving up of pleasure and pain and the disappearance of former happiness and sadness, a mendicant enters and remains in the fourth absorption, without pleasure or pain, with pure equanimity and mindfulness. This is called the fourth absorption.’ And so … I was entering and remaining in the fourth absorption. While I was in that meditation, perception and focus accompanied by pleasure beset me.