وَعَنِ ابْنِ عُمَرَ رَضِيَ اللَّهُ عَنْهُ
قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «إِنَّ الدُّعَاءَ يَنْفَعُ مِمَّا نَزَلَ وَمِمَّا لَمْ يَنْزِلْ فَعَلَيْكُمْ عِبَادَ اللَّهِ بِالدُّعَاءِ»
Ibn Umar reported God’s messenger as saying, “Supplication is beneficial regarding things which have happened and things which have not happened, so devote yourselves to supplication, servants of God.” Tirmidhi transmitted it, and Ahmad transmitted it from Muadh ibn Jabal. Tirmidhi said this is a gharib tradition.
Mishkat al-Masabih 2138, Book 10, Supplications, Hadith 12. 1 min read