612. hadíth
وَ قَالَ رَسُولُ اَللَّهِ صَلَّى اَللَّهُ عَلَيْهِ وَ آلِهِ: "سِبَابُ اَلْمُؤْمِنِ فِسْقٌ وَ قِتَالُهُ كُفْرٌ وَ أَكْلُ لَحْمِهِ مِنْ مَعْصِيَةِ اَللَّهِ وَ حُرْمَةُ مَالِهِ كَحُرْمَةِ دَمِهِ ".
The Messenger of Allah (swt) (peace be upon him and his family) said: "Insulting a believer is wickedness, fighting him is disbelief, consuming his flesh (through backbiting) is disobedience to Allah (swt), and the sanctity of his wealth is like the sanctity of his blood."