The Great Epic of the Bhārata dynasty 12.69.35

12.69.35

sasyābhihāraṃ kuryācca svayameva narādhipaḥ |
asaṃbhave praveśasya dāhayedagninā bhṛśam || 35 ||

Repeatedly assuring his wealthy subjects and the principal officers of the army, he should cause the inhabitants of the open country to take refuge in such forts as are well-protected. He should himself withdraw all stores of grain (from the open country into his forts). If that becomes impossible, he should destroy them completely by fire. He should set men for destroying the crops on the fields of the enemy (by producing disunion among the enemy's subjects). Failing to do this, he should destroy those crops by means of his own troops. He should destroy all the bridges over the rivers in his kingdom. He should bale out the waters of all the tanks in his dominions, or, if incapable of baling them out, cause them to be poisoned. Disregarding the duty of protecting his friends, he should, in view of both present and future circumstances, seek the protection of the ruler of another kingdom who may happen to be the foe of his foe and who may be competent to deal with his foe on the field of battle. He should destroy all the smaller forts in his kingdom. He should also cut down all the smaller trees excepting those that are called Chaitya. He should cause the branches of all the larger trees to be lopped off, but he should not touch the very leaves of those called Chaitya. He should raise outer ramparts round his forts, with enclosures in them, and fill his trenches with water, driving pointed stakes at their bottom and filling them with crocodiles and sharks.