وَعَنْهُ قَالَ: قَالَ رَسُولُ اَللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ -«اَلْمُؤْمِنُ مِرْآةُ اَلْمُؤْمِنِ»
“Every believer is the mirror of his brother.” Related by Abu Dawud with a good chain of narrators.
Bulugh al-Maram 1733, Book 16, The Comprehensive Book, Hadith 99. 1 min read