《资治通鉴·秦纪·秦纪一》
但这时秦王嬴政却不以礼相待，太子丹一怒之下逃回了燕国。秦王政十六年
丹怒，亡归。始皇帝上十六年
However, King Qin Yingzheng treated him disrespectfully, so Crown Prince Dan fled back to the State of Yan in anger. The 16th year of King Qin Zheng 