《资治通鉴·唐纪·唐纪二》
但现在东都的军队有三个不可抵挡：武器精良，这是一；决计深入我方，这是二；粮食吃完了决战，这是三。
今东都兵有三不可当：兵仗精锐，一也；决计深入，二也；食尽求战，三也。
But right now, the Eastern Capital’s troops have three irresistibles: excellent weapons, this is one; determination to reach deep into our territory, this is two; when they have exhausted their food, they will fight to the death, this is three.