《笑林广记·殊禀部》
有个邮差递送紧急公文，当官的恐怕他走得慢，拨一匹马让他骑。邮差赶着马走，别人问他 如此急事，怎么不骑马？ 
铺司递紧急公文，官恐其迟，拨一马骑之，其人赶马而行。人问其 如此急事，何不乘马？ 
There was a man delivering an urgent dispatch; because the official worried that he would be slow, he gave him a horse to ride. The man rode after the horse, so others asked him, "What's so urgent that you're not riding the horse?" 