Yahya related to me from Malik from Muslim ibn Abi Maryam fromAbu Salih as-Samman that Abu Hurayra said, "The actions of people arepresented twice each week, on Monday and Thursday. Every trustingslave is forgiven except for a slave who has enmity between him andhis brother. It is said, 'Leave these two until they turn in tawba.Leave these two until they turn in tawba.' ''
USC-MSA web (English) reference: Book 47, Hadith 18
Arabic reference: Book 47, Hadith 1653