It was narrated from Safwan bin ‘Abdullah bin Safwan said that he was married to a daughter of Abu Darda’. He came to her and found Umm Darda’ there, but he did not find Abu Darda’. She said to him:
“Do you intend to perform Hajj this year?” He said: “Yes.” She said: “Pray to Allah for us to grant us goodness, for the Prophet ﷺ used to say: ‘The supplication of a man for his brother in his absence will be answered. By his head there is an angel who says Amin to his supplication, and every time he prays for his brother, he says: “Amin, and the same for you.’” He said: “Then I went out to the marketplace where I met Abu Darda’, and he told me something similar from the Prophet ﷺ.”

حَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ، حَدَّثَنَا يَزِيدُ بْنُ هَارُونَ، عَنْ عَبْدِ الْمَلِكِ بْنِ أَبِي سُلَيْمَانَ، عَنْ أَبِي الزُّبَيْرِ، عَنْ صَفْوَانَ بْنِ عَبْدِ اللَّهِ بْنِ صَفْوَانَ، قَالَ وَكَانَتْ تَحْتَهُ ابْنَةُ أَبِي الدَّرْدَاءِ فَأَتَاهَا فَوَجَدَ أُمَّ الدَّرْدَاءِ وَلَمْ يَجِدْ أَبَا الدَّرْدَاءِ فَقَالَتْ لَهُ تُرِيدُ الْحَجَّ الْعَامَ قَالَ نَعَمْ . قَالَتْ فَادْعُ اللَّهَ لَنَا بِخَيْرٍ فَإِنَّ النَّبِيَّ ﷺ كَانَ يَقُولُ " دَعْوَةُ الْمَرْءِ مُسْتَجَابَةٌ لأَخِيهِ بِظَهْرِ الْغَيْبِ عِنْدَ رَأْسِهِ مَلَكٌ يُؤَمِّنُ عَلَى دُعَائِهِ كُلَّمَا دَعَا لَهُ بِخَيْرٍ قَالَ آمِينَ وَلَكَ بِمِثْلِهِ " . قَالَ ثُمَّ خَرَجْتُ إِلَى السُّوقِ فَلَقِيتُ أَبَا الدَّرْدَاءِ فَحَدَّثَنِي عَنِ النَّبِيِّ ﷺ بِمِثْلِ ذَلِكَ .