《明史·志·卷三十五》
退出公家官署到私室，则仍然穿素服戴白帽二十七天。
退出公署及私室，则仍素服白帽二十七日。
Withdraw from the public office to the private room, and continue to wear plain clothes and white hats for twenty-seven days.
<s>[INST] Identify the key themes in this Classical Chinese text and explain them in English: 退出公署及私室，则仍素服白帽二十七日。 [/INST] Withdraw from the public office to the private room, and continue to wear plain clothes and white hats for twenty-seven days.</s>
Identify the key themes in this Classical Chinese text and explain them in English: 退出公署及私室，则仍素服白帽二十七日。
user
Withdraw from the public office to the private room, and continue to wear plain clothes and white hats for twenty-seven days.
assistant