The Yaksha asked,—‘What enemy is invincible? What constitutes an incurable disease for man? What sort of a man is called honest and what dishonest?’ Yudhishthira answered,—‘Anger is an invincible enemy. Covetousness constitutes an incurable disease. He is honest that desires the weal of all creatures, and he is dishonest who is unmerciful.’
In plain words: Yudhishthira says anger is an enemy no one can fully defeat, and greed is a sickness with no cure. An honest person wants good for every living being, and a dishonest person has no mercy.