《韩非子·存韩》
如果秦国向前进攻赵国而不能夺取，退而击韩不能攻克，那么冲锋陷阵的士兵疲于野战，运输队伍疲于军内消耗，那就是集合困苦疲劳的军队来对付赵、齐两个大国，这不是秦国所以要进攻消灭韩国的本意。
夫进而击赵不能取，退而攻韩弗能拔，则陷锐之卒勤于野战，负任之旅罢于内攻，则合群苦弱以敌而共二万乘，非所以亡赵之心也。
If Qin attacks Zhao but cannot capture, retreats and attacks Han but cannot take the city, then the soldiers who fight in the battle will be exhausted in the field, and the transportation team will be exhausted for military consumption, which means gathering tired and fatigued troops to fight against the two major countries of Zhao and Qi. This is not the original intention of Qin to attack and destroy Han.