Mahabharata Bhishma Parva Chapter 3:5

Mahabharata Bhishma Parva (Jamvu-khanda Nirmana Parva) Chapter 3:5 They who utter cheerful shouts having penetrated into the divisions of the foe, who utter even kind words, to the enemy, and who, before striking, forewarn the foe, win victory. The objects of hearing, vision, taste, touch, and smell, without undergoing any change for the worse, become auspicious. This also is another indication of a victorious army, viz., there is joy among the combatants at all time. This also is another indication of success, viz. the winds that blow, the clouds, and the birds, all become favourable; while the clouds (so favourable) and the rain-bows drop beneficial showers. These, O king, are the indications of armies to be crowned with victory, while O monarch, all these become otherwise in the case of those that are about to be destroyed. Whether the army be small or large, cheerfulness, as an attribute of the combatants, is said to be a certain indication of victory. One soldier, struck with panic, can cause even a large army to take fright and fly. And when an army, struck with panic, takes to flight, it causes even heroic warriors to take fright. If a large army is once broken and put to rout, it cannot like a herd of deer disordered in fright or a mighty current of water be easily checked. If a large army is once routed, it is incapable of being rallied; on the other hand, beholding it broken, even those well-skilled in battle, O Bharata, become heartless. Beholding soldiers struck with fear and flying, the panic spreads in other directions, and soon, O king, the whole army is broken and flies in all directions. And when an army is routed, even brave leaders, O king, at the head of large divisions consisting of the four kinds of forces, are incapable of rallying them. An intelligent man, always exerting himself with activity, should strive (to win success) by the aid of means. It is said that that success which is won by negotiation and other means is the very best. That which is achieved by producing disunion (among the foe) is indifferent. While that success, O king, which is won by battle, is the worst. In battle are many evils, the initial one, as it is said, being slaughter. Even fifty brave men who know one another, who are underpressed, who are free from family ties, and who are firmly resolved, can crush a large army. Even five, six, seven men, who are unretreating, win victory. Vinata's son Garuda, O Bharata, beholding even a large concourse of birds, asketh not the aid of many followers (to vanquish them). The strength in number, therefore of an army is not always the cause of victory. Victory is uncertain. It depends on chance. Even they that become victorious have to sustain loss.