《左传·哀公·哀公十八年》
请求任命副手，楚惠王说： 寝尹、工尹，都是为先君出过力的人。 
王曰： 寝尹、工尹，勤先君者也。 
Requesting to appoint an assistant, King Hui of Chu said, "Yin, the assistant official in charge of sleeping quarters and Yin, the assistant official in charge of crafts, these were all people who had served for the former ruler."