This sentence means ""He who marches a hundred miles in haste to compete with the enemy for advantage will be in danger of losing his general". This also elaborates on the harmful effects of a laborious expedition. Ancient military books on the labor division expedition is a big taboo, because one, the military is tricky also, labor division expedition is bound to be easily exposed; two, labor division expedition, soldiers lack of will be trapped, supply is not favorable, easy to defeat, all have quite a discourse.