[278] Bhikkhus, there are two persons who, I say, cannot easily be repaid. Which two? One's mother and one's father. Bhikkhus, even if one were to carry one's mother about on one shoulder and one's father on the other shoulder, living for a hundred years, enduring for a hundred years, and were to attend upon them with anointing, massaging, bathing, and rubbing of the limbs, and even if they were to discharge their urine and excrement right there — even so, bhikkhus, one would not have done enough for one's mother and father, nor repaid them. And even if, bhikkhus, one were to establish one's mother and father in supreme sovereign kingship over this great earth abounding in the seven treasures — even so, bhikkhus, one would not have done enough for one's mother and father, nor repaid them. For what reason? Because, bhikkhus, mothers and fathers are of great help to their children: they bring them up, they nourish them, they show them this world. But, bhikkhus, whoever encourages, settles, and establishes his faithless mother and father in the accomplishment of faith (saddhā-sampadā); encourages, settles, and establishes his immoral mother and father in the accomplishment of virtue (sīla-sampadā); encourages, settles, and establishes his stingy mother and father in the accomplishment of generosity (cāga-sampadā); encourages, settles, and establishes his unwise mother and father in the accomplishment of wisdom (paññā-sampadā) — to this extent, bhikkhus, one has both done enough for one's mother and father and repaid them.
English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.