The Buddha’s ReviewingPaccavekkhaṇasutta

So I have heard.Evaṁ me sutaṁ— At one time the Buddha was staying near Sāvatthī in Jeta’s Grove, Anāthapiṇḍika’s monastery.ekaṁ samayaṁ bhagavā sāvatthiyaṁ viharati jetavane anāthapiṇḍikassa ārāme. Now at that time the Buddha was sitting reviewing his own giving up of many bad, unskillful qualities, and the many skillful qualities he had fully developed.Tena kho pana samayena bhagavā attano aneke pāpake akusale dhamme pahīne paccavekkhamāno nisinno hoti, aneke ca kusale dhamme bhāvanāpāripūriṁ gate.

Then, knowing the many bad, unskillful qualities that he had given up and the many skillful qualities he had fully developed, on that occasion the Buddha expressed this heartfelt sentiment:Atha kho bhagavā attano aneke pāpake akusale dhamme pahīne viditvā aneke ca kusale dhamme bhāvanāpāripūriṁ gate tāyaṁ velāyaṁ imaṁ udānaṁ udānesi:

“What was before then was not;“Ahu pubbe tadā nāhu, what before was not then was.nāhu pubbe tadā ahu; It never was, nor will it be,Na cāhu na ca bhavissati, nor is it found today.”na cetarahi vijjatī”ti.