Mbh 3.29.1b

And the wise man also who though presecuted, suffereth not his wrath to be roused, joyeth in the other world--having passed his persecutor over in indifference. It is for this reason hath it been said that a wise man, whether strong or weak, should ever forgive his persecutor even when the latter is in the straits. It is for this, O Krishna, that the virtuous applaud them that have conquered their wrath. Indeed, it is the opinion of the virtuous that the honest and forgiving man is ever victorious. Truth is more beneficial than untruth; and gentleness than cruel behaviour. How can one like me, therefore, even for the purpose of slaying Duryodhana, exhibit anger which hath so many faults and which the virtuous banish from their souls? They that are regarded by the learned of foresight, as possessed of (true) force of character, are certainly those who are wrathful in outward show only. Men of learning and of true insight call him to be possessed of force of character who by his wisdom can suppress his risen wrath. O thou of fair hips, the angry man seeth not things in their true light. The man that is angry seeth not his way, nor respecteth persons. The angry man killeth even those that deserve not to be killed. The man of wrath slayeth even his preceptors. Therefore, the man possessing force of character should ever banish wrath to a distance. The man that is overwhelmed with wrath acquireth not with ease generosity, dignity, courage, skill, and other attributes belonging to real force of character. A man by forsaking anger can exhibit proper energy, whereas, O wise one, it is highly difficult for the angry man to exhibit his energy at the proper time! The ignorant always regard anger as equivalent to energy. Wrath, however hath been given to man for the destruction of the world. The man, therefore, who wisheth to behave properly, must ever forsake anger.