حَدَّثَنِي أَحْمَدُ بْنُ عُمَرَ بْنِ حَفْصٍ الْوَكِيعِيُّ، حَدَّثَنَا مُحَمَّدُ بْنُ فُضَيْلٍ، حَدَّثَنَا أَبِي، عَنْ طَلْحَةَ بْنِ عُبَيْدِ اللَّهِ بْنِ كَرِيزٍ، عَنْ أُمِّ الدَّرْدَاءِ، عَنْ أَبِي الدَّرْدَاءِ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " مَا مِنْ عَبْدٍ مُسْلِمٍ يَدْعُو لأَخِيهِ بِظَهْرِ الْغَيْبِ إِلاَّ قَالَ الْمَلَكُ وَلَكَ بِمِثْلٍ " .
Abu Dharr reported that Allah's Messenger (PBUH) said: There is no believing servant who supplicates for his brother behind his back (in his absence) that the Angels do not say: The same be for you too. Translation Not Available
Book Ref: Sahih Muslim Book 48 Hadith 6588
Web Ref: Sahih Muslim Book 35 Hadith 2732 a