وَعَنْ أَبِي الدَّرْدَاءِ رَضِيَ اللَّهُ عَنْهُ قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: " دعوةُ الْمُسْلِمِ لِأَخِيهِ بِظَهْرِ الْغَيْبِ مُسْتَجَابَةٌ عِنْدَ رَأْسِهِ مَلَكٌ مُوَكَّلٌ كُلَّمَا دَعَا لِأَخِيهِ بِخَيْرٍ قَالَ الْمَلَكُ الْمُوَكَّلُ بِهِ: آمِينَ وَلَكَ بِمِثْلٍ ". رَوَاهُ مُسلم

Abu Darda’ reported God’s messenger as saying, “A Muslim’s supplication for an absent brother receives an answer. An angel is stationed at his head, and as often as he makes supplication that his brother may be given what is good the angel who is put in charge of him says, ‘Amen, and may you receive the like’.” Muslim transmitted it.