《新唐书·列传·卷八十》
仆固怀恩叛变，浑瑊带自己的部队归属郭子仪，碰到父亲释之逝世，守丧期未满被征召为朔方行营兵马使。
怀恩反，瑊以所部归子仪，会释之丧，起复朔方行营兵马使。
Pu Gu Huaien rebelled, and Hun Xu led his own troops to Guo Ziyi. When his father Shi Zhi died, he was called up as the commander of the Shuofang army before the end of the mourning period.
<s>[INST] Identify the key themes in this Classical Chinese text and explain them in English: 怀恩反，瑊以所部归子仪，会释之丧，起复朔方行营兵马使。 [/INST] Pu Gu Huaien rebelled, and Hun Xu led his own troops to Guo Ziyi. When his father Shi Zhi died, he was called up as the commander of the Shuofang army before the end of the mourning period.</s>
Identify the key themes in this Classical Chinese text and explain them in English: 怀恩反，瑊以所部归子仪，会释之丧，起复朔方行营兵马使。
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Pu Gu Huaien rebelled, and Hun Xu led his own troops to Guo Ziyi. When his father Shi Zhi died, he was called up as the commander of the Shuofang army before the end of the mourning period.
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