عَنِ النُّعْمَانِ بْنِ بَشِيرٍ قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «الدُّعَاءُ هُوَ الْعِبَادَةُ» ثُمَّ قَرَأَ: (وَقَالَ رَبُّكُمُ ادْعُونِي أَسْتَجِبْ لَكم) رَوَاهُ أَحْمَدُ وَالتِّرْمِذِيُّ وَأَبُو دَاوُدَ وَالنَّسَائِيُّ وَابْنُ مَاجَه

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 Mu'adh b. Jabal. Tirmidhi said this is a gharib tradition.