Sayyiduna Anas bin Malik (may Allah be pleased with him) reports that the Prophet (peace and blessings be upon him) said: "The believer is the mirror of (another) believer."
Al-Bazzar recorded it, and al-Tabarani in al-Mu'jam al-Awsat; its chain contains Uthman bin Muhammad, one of the descendants of Rabi'ah bin Abi Abd al-Rahman, about whom Ibn al-Qattan said: Error predominates in his hadith; the rest of its narrators are thiqat (trustworthy).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الفتن - أعاذنا الله منها / 12120