It is narrated from Sayyiduna Abu Hurairah, may Allah be pleased with him, that indeed the Prophet, peace and blessings be upon him, said: "A believer is the mirror of a believer."
Hadith Referenceمسند الشهاب / 125
Hadith Gradingمحدثین:إسناده صحيح
Hadith Takhrij«إسناده صحيح ، وأخرجه أبو داود : 4918، والادب المفرد : 239»
Brief Explanation
Explanation: In this hadith, a believer is described as a mirror for another believer. Just as a mirror silently displays the virtues and flaws of the one who looks into it, without any addition or omission, and only to that person, in the same way, a believer also makes his brother aware of his virtues as well as his flaws so that he may reform himself. Moreover, a believer reveals his brother’s flaws only to him and does not inform others, thereby avoiding slander and backbiting.