《明史·列传·卷八十七》
严嵩又想让他的儿子世蕃做尚宝丞，郑晓说： 治中升做知府，符合常例；升做尚宝丞，过去没这个先例。 
嵩欲以子世蕃为尚宝丞，晓曰： 治中迁知府，例也。迁尚宝丞，无故事。 
Yan Song then wanted to make his son Shifan Supervisor of the Bureau of Precious Goods, and Zheng Xiao said: “It is generally accepted for the Administrator to be promoted to the position of Prefect; it is not a precedent to be promoted to the position of the Supervisor of the Bureau of Precious Goods.”
<s>[INST] Kindly elucidate the central themes in this passage in English: 嵩欲以子世蕃为尚宝丞，晓曰： 治中迁知府，例也。迁尚宝丞，无故事。  [/INST] Yan Song then wanted to make his son Shifan Supervisor of the Bureau of Precious Goods, and Zheng Xiao said: “It is generally accepted for the Administrator to be promoted to the position of Prefect; it is not a precedent to be promoted to the position of the Supervisor of the Bureau of Precious Goods.”</s>
Kindly elucidate the central themes in this passage in English: 嵩欲以子世蕃为尚宝丞，晓曰： 治中迁知府，例也。迁尚宝丞，无故事。
user
Yan Song then wanted to make his son Shifan Supervisor of the Bureau of Precious Goods, and Zheng Xiao said: “It is generally accepted for the Administrator to be promoted to the position of Prefect; it is not a precedent to be promoted to the position of the Supervisor of the Bureau of Precious Goods.”
assistant