《汉书·传·万石卫直周张传》
石建每五天休假回去看望父亲，进入孩子的房间，私下询问仆人，并取走父亲的内衣内裤和便器，亲自洗濯，然后再给仆人，不敢让万石君知道，而且经常这样做。
每五日洗沐归谒亲，入子舍，窃问侍者，取亲中裙厕牏，身自浣洒，复与侍者，不敢令万石君知之，以为常。
Every five days, Shi Jian would go home on leave to visit his father, go into the servants' quarters, make private inquiries to the servants, and collect his father's undergarments and bedpan to wash them in person before handing them back to the servants, without letting Wanshi Jun know, and he did this regularly.