رِيَاضُ الصَّالِحِينَ
Riyad as-Salihin 1494
The Book of Du'a (Supplications)
The Excellence of Supplicating in one's Absence
وَعَنْ أَبِي الدَّرْدَاءِ رَضِيَ اللَّهُ عَنْهُ أَنَّهُ سَمِعَ رَسُولَ اللَّهِ صَلَّى اللَّه عَلَيْهِ وَسَلَّمَ يَقُولُ: مَا مِنْ عَبْدٍ مُسْلِمٍ يَدْعُو لأَخِيهِ بِظَهْرِ الْغَيْبِ إِلاَّ قَالَ الْمَلَكُ وَلَكَ بِمِثْلٍ ((رَوَاهُ مُسْلِم)).
Abud-Darda' (May Allah be pleased with him) reported: I heard the Messenger of Allah (ﷺ) saying, "Whenever a Muslim supplicates for his (Muslim) brother in his absence, the angels say: 'May the same be for you too'." [Muslim].
Riyad as-Salihin, 1494