以ㄧˇ子ㄗˇ之ㄓ矛ㄇㄠˊyǐzǐzhīmáo，攻ㄍㄨㄥ子ㄗˇ之ㄓ盾ㄉㄨㄣˋgōngzǐzhīdùn

  1. 以你的矛來戳你的盾。比喻用對方的觀點、理論等來反駁對方。例 「以子之矛，攻子之盾，對方頓時啞口無言」。

英lit. use sb's spear to attack his shield (idiom, derived from Han Feizi 韓非子)​; turning a weapon against its owner, fig. to attack an opponent using his own devices, hoist with his own petard