《战国策·燕一·齐伐宋宋急》
攻破宋国，侵占楚国的淮北，使齐国的领土扩大了，也就是使仇敌强大了本国弱小了。
破宋，残楚淮北，肥大齐，雠强而国弱也。
If Song is conquered and Chu's Huaibei is occupied, Qi's territory will be expanded, which means that the enemy will become stronger and the country will become weaker.