《史记·三十世家·晋世家》
献公即位时，重耳二十一岁。
献公即位，重耳年二十一。
When Duke Xian ascended to the throne, Chong'er was twenty-one years old.
<s>[INST] Kindly elucidate the central themes in this passage in English: 献公即位，重耳年二十一。 [/INST] When Duke Xian ascended to the throne, Chong'er was twenty-one years old.</s>
Kindly elucidate the central themes in this passage in English: 献公即位，重耳年二十一。
user
When Duke Xian ascended to the throne, Chong'er was twenty-one years old.
assistant