《旧五代史·后汉·列传六》
当杜重威请命投降时，张琏等人请朝廷信守誓言，高祖答应让张琏等人回到契丹国去。
及重威请命，琏等邀朝廷信誓，诏许琏等却归本土。
When Du Chongwei asked to capitulate, Zhang Lian and his men asked the imperial court to keep its promise, as Gaozu had promised to let Zhang Lian and his men return to Qidan.
<s>[INST] Identify the key themes in this Classical Chinese text and explain them in English: 及重威请命，琏等邀朝廷信誓，诏许琏等却归本土。 [/INST] When Du Chongwei asked to capitulate, Zhang Lian and his men asked the imperial court to keep its promise, as Gaozu had promised to let Zhang Lian and his men return to Qidan.</s>
Identify the key themes in this Classical Chinese text and explain them in English: 及重威请命，琏等邀朝廷信誓，诏许琏等却归本土。
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When Du Chongwei asked to capitulate, Zhang Lian and his men asked the imperial court to keep its promise, as Gaozu had promised to let Zhang Lian and his men return to Qidan.
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