《后汉书·列传·郭杜孔张廉王苏羊贾陆》
当他进入郡界，就微服巡行，带着一名童子，查看县邑，采问风谣，然后再进。
当入郡界，乃羸服间行，侍童子一人，观历县邑，采问风谣，然后乃进。
When he entered the county, he traveled in private, taking only a boy with him. He inspected the counties and townships, inquired about the rumors, and then entered.