[以子之矛,攻子之盾, yǐ zǐ zhī máo, gōng zǐ zhī dùnㄧˇ ㄗˇ ㄓ ㄇㄠˊ, ㄍㄨㄥ ㄗˇ ㄓ ㄉㄨㄣˋ] lit. use sb's spear to attack his shield (成语 saw, derived from Han Feizi 韓非子|韩非子); turning a weapon against its owner; fig. to attack an opponent using his own devices; hoist with his own petard, See Also: 成语, 韓非子, 韩非子