Sahih Muslim 2733
Sahih Muslim · Book 48: The Book Pertaining to the Remembrance of Allah, Supplication, Repentance and Seeking Forgiveness · The Virtue Of Praying For The Muslims In Their Absence
Safwan (and he was Ibn 'Abdullah b. Safwan, and he had been married to Umm Darda') reported:
حَدَّثَنَا إِسْحَاقُ بْنُ إِبْرَاهِيمَ ، أَخْبَرَنَا عِيسَى بْنُ يُونُسَ ، حَدَّثَنَا عَبْدُ الْمَلِكِ بْنُ أَبِي، سُلَيْمَانَ عَنْ أَبِي الزُّبَيْرِ ، عَنْ صَفْوَانَ، - وَهُوَ ابْنُ عَبْدِ اللَّهِ بْنِ صَفْوَانَ - وَكَانَتْ تَحْتَهُ الدَّرْدَاءُ قَالَ قَدِمْتُ الشَّامَ فَأَتَيْتُ أَبَا الدَّرْدَاءِ فِي مَنْزِلِهِ فَلَمْ أَجِدْهُ وَوَجَدْتُ أُمَّ الدَّرْدَاءِ فَقَالَتْ أَتُرِيدُ الْحَجَّ الْعَامَ فَقُلْتُ نَعَمْ . قَالَتْ فَادْعُ اللَّهَ لَنَا بِخَيْرٍ فَإِنَّ النَّبِيَّ صلى الله عليه وسلم كَانَ يَقُولُ " دَعْوَةُ الْمَرْءِ الْمُسْلِمِ لأَخِيهِ بِظَهْرِ الْغَيْبِ مُسْتَجَابَةٌ عِنْدَ رَأْسِهِ مَلَكٌ مُوَكَّلٌ كُلَّمَا دَعَا لأَخِيهِ بِخَيْرٍ قَالَ الْمَلَكُ الْمُوَكَّلُ بِهِ آمِينَ وَلَكَ بِمِثْلٍ " . قَالَ فَخَرَجْتُ إِلَى السُّوقِ فَلَقِيتُ أَبَا الدَّرْدَاءِ فَقَالَ لِي مِثْلَ ذَلِكَ يَرْوِيهِ عَنِ النَّبِيِّ صلى الله عليه وسلم .
I visited Abu Darda's house in Syria. I did not find him there but Umm Darda' (was present at the house). She said: Do you intend to perform Hajj during this year? I said: Yes. She said: Do supplicate Allah for blessings upon us, for Allah's Apostle (may peace be upon hiin) used to say: The supplication of a Muslim for his brother at his back (in his absence) is responded so long as he makes a supplica- tion for blessings for his brother and the commissioned Angel says: Amen, and says: May it be for you too I I went to the bazar and met Abfi Dardi' and he narrated like this from Allah's Messenger (ﷺ).