Abu Hurairah (RAA) narrated that the Messenger of Allah (ﷺ) said:
"Every believer is the mirror of his brother." Related by Abu Dawud with a good chain of narrators. (RU)
English reference (RU): Book 16, Hadith 1578 (RU)
Arabic reference (RU): Book 16, Hadith 1535 (RU)