Mahabharata 3.34.55

3.34.55

sa kṣātraṃ hṛdayaṃ kṛtvā tyaktvedaṃ śithilaṃ manaḥ |
vīryamāsthāya kaunteya dhuramudvaha dhuryavat || 55 ||

Therefore, O thou of the Kuru race, making thy heart what it ought to be, agreeably to the order to which thou belongest, and casting away this course of feebleness, summon thy energy and bear thy weight like one that beareth it manfully. No king, O monarch, could ever acquire the sovereignty of the earth or prosperity or affluence by means of virtue alone. Like a fowler earning his food in the shape of swarms of little easily-tempted game, by offering them some attractive food, doth one that is intelligent acquire a kingdom, by offering bribes unto low and covetous enemies. Behold, O bull among kings, the Asuras, though elder brothers in possession of power and affluence, were all vanquished by the gods through stratagem. Thus, O king, everything belongeth to those that are mighty. And, O mighty-armed one, slay thy foes, having recourse to stratagem. There is none equal unto Arjuna in wielding the bow in battle. Nor is there anybody that may be equal unto me in wielding the mace. Strong men, O monarch, engage in battle depending on their might, and not on the force of numbers nor on information of the enemy's plans procured through spies. Therefore, O son of Pandu exert thy might. Might is the root of wealth. Whatever else is said to be its root is really not such. As the shade of the tree in winter goeth for nothing, so without might everything else becometh fruitless.