《汉书·纪·高帝纪上》
项羽怀恨楚怀王原先不允许他沛公一道西进入关，而是派他北进救赵，以致失去了 先入定关中的为王 的机会。
羽怨怀王不肯令与沛公俱西入关而北救赵，后天下约。
Xiang Yu held a grudge because King Huai of Chu did not initially allow him to enter Guanzhong together with Pei Gong, but instead sent him to the north to save Zhao, which caused him to miss the opportunity to enter Guanzhong first and become king.
<s>[INST] Rewrite the following English passage in the style of Classical Chinese: Xiang Yu held a grudge because King Huai of Chu did not initially allow him to enter Guanzhong together with Pei Gong, but instead sent him to the north to save Zhao, which caused him to miss the opportunity to enter Guanzhong first and become king. [/INST] 羽怨怀王不肯令与沛公俱西入关而北救赵，后天下约。</s>
Rewrite the following English passage in the style of Classical Chinese: Xiang Yu held a grudge because King Huai of Chu did not initially allow him to enter Guanzhong together with Pei Gong, but instead sent him to the north to save Zhao, which caused him to miss the opportunity to enter Guanzhong first and become king.
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羽怨怀王不肯令与沛公俱西入关而北救赵，后天下约。
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