《汉书·志·郊祀志上》
他的子孙把疆域扩展到黄河沿岸，于是在雍城定都。
子孙饮马于河，遂都雍。
His descendants expanded their territory to the Yellow River, so they settled in Yongcheng.
<s>[INST] Identify the key themes in this Classical Chinese text and explain them in English: 子孙饮马于河，遂都雍。 [/INST] His descendants expanded their territory to the Yellow River, so they settled in Yongcheng.</s>
Identify the key themes in this Classical Chinese text and explain them in English: 子孙饮马于河，遂都雍。
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His descendants expanded their territory to the Yellow River, so they settled in Yongcheng.
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