《左传·定公·定公四年》
楚国自从昭王即位以后，没有一年不和吴国交战，蔡昭侯仗着这个，把他的儿了乾和一个大夫的儿子放在吴国作为人质。
楚自昭王即位，无岁不有吴师。蔡侯因之，以其子乾与其大夫之子为质于吴。
Since King Zhao ascended the throne, Chu had not fought with Wu for a year, and Cai Zhao Hou took advantage of this to put his son Qian and the son of a doctor in Wu as hostages.