《礼记·檀弓下》
于是公子重耳对来使说： 承蒙贵国国君派足下来慰向出亡在外的臣子，我流亡在外，而父亲死了，不能星夜奔回国内在灵位前哭泣，以抒发内心的悲哀，以至于使贵国国君为我担忧。
公子重耳对客曰： 君惠吊亡臣重耳，身丧父死，不得与于哭泣之哀，以为君忧。
Therefore Duke Chong'er said to the envoy, "I thank the lord of your country for sending you to offer condolences to a subject in exile. I'm in exile, and my father died. I couldn't rush back to the country overnight to cry before the spirit tablet, to express my grief, so much so that the lord of your country is worried about me."
<s>[INST] Kindly elucidate the central themes in this passage in English: 公子重耳对客曰： 君惠吊亡臣重耳，身丧父死，不得与于哭泣之哀，以为君忧。 [/INST] Therefore Duke Chong'er said to the envoy, "I thank the lord of your country for sending you to offer condolences to a subject in exile. I'm in exile, and my father died. I couldn't rush back to the country overnight to cry before the spirit tablet, to express my grief, so much so that the lord of your country is worried about me."</s>
Kindly elucidate the central themes in this passage in English: 公子重耳对客曰： 君惠吊亡臣重耳，身丧父死，不得与于哭泣之哀，以为君忧。
user
Therefore Duke Chong'er said to the envoy, "I thank the lord of your country for sending you to offer condolences to a subject in exile. I'm in exile, and my father died. I couldn't rush back to the country overnight to cry before the spirit tablet, to express my grief, so much so that the lord of your country is worried about me."
assistant