Paccavekkhaṇa sutta: The Buddha’s Reviewing

So I have heard. At one time the Buddha was staying near Sāvatthī in Jeta’s Grove, Anāthapiṇḍika’s monastery. 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.

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:

“What was before then was not;
what before was not then was.
It never was, nor will it be,
nor is it found today.”