Mbh 5.38.1d

A foe that deserveth death, when brought under subjection should never be set free. If one be weak one should pay court to one’s foe that is stronger, even if the latter deserves death; but one should kill that foe as soon as one commandeth sufficient strength, for, if not killed, dangers soon arise from him. One should, with an effort, control his wrath against the gods, kings, Brahmanas, old men, children, and those that are helpless. He that is wise should avoid unprofitable quarrels such as fools only engage in. By this one winneth great fame in this world and avoideth misery and unhappiness. People never desire him for a master whose grace is fruitless and whose wrath goest for nothing, like women never desiring him for a husband who is a eunuch. Intelligence doth not exist for the acquisition of wealth, nor is idleness the cause of adversity; the man of wisdom only knoweth, and not others, the cause of the diversities of condition in this world. The fool, O Bharata, always disregardeth those that are elderly in years, and eminent in conduct and knowledge, in intelligence, wealth, and lineage. Calamities soon come upon them that are of wicked disposition, devoid of wisdom, envious, or sinful, foul-tongued, and wrathful. Absence of deceitfulness, gifts, observance of the established rules of intercourse, and speech well-controlled, bring all creatures under subjection. He that is without deceitfulness, he that is active, grateful, intelligent, and guileless, even if his treasury be empty, obtaineth friends, counsellors, and servants. Intelligence, tranquillity of mind, self-control, purity, absence of harsh speech and unwillingness to do anything disagreeable to friends,--these seven are regarded as the fuel of prosperity’s flame. The wretch who doth not give to others their due, who is of wicked soul, who is ungrateful, and shameless, should, O king, be avoided.