《汉书·传·循吏传》
宣帝因为龚遂年事已高，不能担当公卿重任，就拜他做水衡都尉，议曹王生任水衡丞，用以表示对龚遂的褒奖和尊重。
上以遂年老不任公卿，拜为水衡都尉，议曹王生为水衡丞，以褒显遂云。
Because Gong Sui was old and could not bear the heavy responsibility of a minister, Emperor Xuandi appointed him as the water Heng capital, and Wang Sheng, the adviser, as the water Heng Cheng, as a reward and respect to Gong Sui.