So if God would give an important task to a certain person, the first things he does are to temper his will power, fatigue his muscles and bones, starve his stomach and destitute his body. God would not make any kind of his action satisfactory as he wishes in order to shock his heart, make his temperament persistent and dauntless, and increase his ability.
故天将降大任于斯人也，必先苦其心志，劳其筋骨，饿其体肤，空乏其身，行拂乱其所为。所以动心忍性，曾益其所不能。------孟子
When Heaven is about to place a great responsibility on a great man, it always first frustrates his spirit and will, exhausts his muscles and bones, exposes him to starvation and poverty, harasses him by troubles and setbacks so as to stimulate his spirit, toughen his nature and enhance his abilities.
【常见译文】
孟子说：“舜从田间劳动中成长起来，傅说从筑墙的工作中被 选拔出来，
胶鬲被选拔于鱼盐的买卖之中，管仲被提拔于囚犯的位置上，孙叔敖从海边被 发现，百里奚从市场上被选拔。所以，上天将要把重大使命降落到某人身上， 一定要先使他的意志受到磨练，使他的筋骨受到劳累，使他的身体忍饥挨饿， 使他备受穷困之苦，做事总是不能顺利。这样来震动他的心志，坚韧他的性情， 增长他的才能。人总是要经常犯错误，然后才能改正错误；。心气郁结，殚思 极虑，然后才能奋发而起；显露在脸色上，表达在声音中，然后才能被人了解。 一个国家，内没有守法的大臣和辅佐的贤士，外没有敌对国家的忧患，往往容 易亡国。由此可以知道， 忧患使人生存，安逸享乐却足以使人败亡。”
天准备把重大任务交付这个人，一定要先折磨他的心志，劳累他的筋骨，饥饿他的肠胃，穷尽他的体力，使他的所作所为都不能如意，这样就可以震撼他的心思，坚忍他的性格，由此增加他所缺少的才干。人们总是犯了过错，才有机会改正；心意受限制，思虑受阻碍，才会发奋振作；表现在脸色上，发抒在言语中，才会被人了解。