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，增益其所不能 (《孟子·告子下》)

When Heaven intends to bestow a great mission on a person,it makes him suffer in mind and body.It makes him endure starvation,and subjects him to poverty,difficulties and all kinds of tests so as to harden his will power,toughen his nature and increase his capabilities;Thus,when heaven is about to confer a great office on any man,it first exercises his mind with suffering,and his sinews and bones with toil.It exposes his body to hunger,and subjects him to extreme poverty.It confounds his undertakings.By all these methods it stimulates his mind,hardens his nature,and removes his incompetence.(Mencius)