《资治通鉴·汉纪·汉纪三》
高帝驻居晋阳，听说冒顿单于驻居在代谷，便想要去攻打他，就派人去侦察匈奴。
上居晋阳，闻冒顿居代谷，欲击之。
The first emperor settled in Jin Yang. When hearing that Maodun Shanyu lives in Daigu, he wants to attack him, so he sends someone to detect Xiongnu.