《战国策·燕二·苏代为燕说齐》
苏代为燕国去游说齐国，没有见齐威王之前，先对淳于髡说道： 有一个卖骏马的人，接连三天早晨守候在集市里，也无人知道他的马是一匹骏马。
苏代为燕说齐，未见齐王，先说淳于髡曰： 人有卖骏马者，比三旦立于市，人莫知之。
Su Dai went to the State of Qi as an envoy for the State of Yan. Before he met King Wei of Qi, he first said to Chunyu Kun, There was a man who sold a horse, and he waited in the market for three consecutive mornings but no one knew his horse was a steed.