抵瑕蹈隙

Explanation: Gap: cracks, gaps. That attack other people's weaknesses or errors. 　　Source: Tangliu Zong Yuan "Q" and servant is shallower and narrower Jian Pi, jump floating Woze, arrived in Eritrea flaw depression. " 　　Examples: To ask for help, want to pick people ~ cheap, we must first understand the law of nations, or delegate authority everywhere. (High-Yang "Qing Unofficial History" the book)