《汉书·传·游侠传》
于是暗暗告诉尉史说： 这个人是我所敬重的，到征用值更之卒时请免用他。 
乃阴请尉史曰： 是人吾所重，至践更时脱之。 
And so he secretly told the military registrar: this is someone I respect, when you are conscripting for night watchmen please exempt him.