During the Eastern Han Dynasty, Zhao Zi, the Administrator of Dunhuang, recommended Cao Hao to serve as the Magistrate of Xingyang County.

Later, when Zhao Zi was transferred to Donghai and passed through Xingyang, Cao Hao and his subordinates waited at a junction to greet him, hoping to persuade him to stay for a temporary rest. However, Zhao Zi, wishing not to cause any trouble or disturbance, did not stop. His carriage quickly sped past.

Cao Hao intended to escort him further, perhaps to the Ten-Mile Long Pavilion just outside the city. But even by the time Cao Hao reached the pavilion, Zhao Zi's carriage had already vanished far into the distance, leaving Cao Hao completely unable to catch up, as if gazing at the dust it left behind but never reaching it.