Mbh 12.69.2d

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.[219] 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.[220] 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. He should keep small openings in his walls for making sallies from his fort, and carefully make arrangements for their defence like that of the greater gates.[221] In all his gates he should plant destructive engines. He should plant on the ramparts (of his forts) Sataghnis and other weapons. He should store wood for fuel and dig and repair wells for supply of water to the garrison. He should cause all houses made of grass and straw to be plastered over with mud, and if it is the summer month, he should, from fear of fire, withdraw (into a place of safety) all the stores of grass and straw. He should order all food to be cooked at night. No fire should be ignited during the day, except for the daily homa.