The Yaksha asked,—‘What is the highest duty in the world? What is that virtue which always beareth fruit? What is that which if controlled, leadeth not to regret? And who are they with whom an alliance cannot break?’ Yudhishthira answered,—‘The highest of duties is to refrain from injury: the rites ordained in the Three (Vedas) always bear fruit: the mind, if controlled, leadeth to no regret: and an alliance with the good never breaketh.’

In plain words: Yudhishthira says the highest duty is not to harm anyone, rituals taught in the Vedas always bring results, a controlled mind never leads to regret, and friendship with good people never breaks.