《三国志·蜀书·刘彭廖李刘魏杨传》
等到刘备进入蜀地，从葭萌返回进攻刘璋，当时刘封二十多岁，身怀武艺，气力过人，率兵和诸葛亮、张飞等人一起，逆流西上，所到的地方全都攻克。
及先主入蜀，自葭萌还攻刘璋，时封年二十馀，有武艺，气力过人，将兵俱与诸葛亮、张飞等溯流西上，所在战克。
When Liu Bei entered Shu, he fought his way back from Jiamo to attack Liu Zhang. At the time, Liu Feng was in his twenties and was skilled in martial arts and had superhuman strength. Together with Generals such as Zhuge Liang and Zhang Fei, he led his troops to advance against the current and westward. They conquered every place they went.