《资治通鉴·梁纪·梁纪十一》
于是高乾率十余骑人马与封隆之的儿子封子绘一起秘密至滏口求见高欢，高乾劝高欢说： 尔硃氏残暴叛逆，人神共怨，凡是明白事理的人，谁不想奋起讨伐！
乃将十馀骑与封隆之子子绘潜谒欢于滏口，说欢曰： 尔硃酷逆，痛结人神，凡曰有知，莫不思奋。
So Gao Qian led more than ten cavalries and went with Feng Longzhi's son Feng Zihui to Fukou in secret to meet Gao Huan. Gao Qian advised Gao Huan, "The Erzhu clan is brutal and rebellious, everyone resents them , all those people who understand the situation, who wouldn't want to punish them?"