عَنِ النُّعْمَانِ بْنِ بَشِيرٍ رَضِيَ اللَّهُ عَنْهُ قَالَ قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ إِنَّ الدُّعَاءَ هُوَ الْعِبَادَةُ ثُمَّ قَرَأَ وَقَالَ رَبُّكُمُ ادْعُونِي أَسْتَجِبْ لَكُمْ إِنَّ الَّذِينَ يَسْتَكْبِرُونَ عَنْ عِبَادَتِي سَيَدْخُلُونَ جَهَنَّمَ دَاخِرِينَ [غافر: 60]
It is narrated from Sayyiduna Nu’man bin Bashir (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: Indeed, supplication is worship itself. Then the Prophet (peace and blessings be upon him) recited this verse: {وَقَالَ رَبُّکُمْ ادْعُونِی أَسْتَجِبْ لَکُمْ إِنَّ الَّذِینَ یَسْتَکْبِرُونَ عَنْ عِبَادَتِی سَیَدْخُلُونَ جَہَنَّمَ دَاخِرِینَ} … And your Lord has said: Call upon Me, I will respond to your supplications. Surely those who are too proud to worship Me will soon enter Hell, humiliated. (Surah Ghafir: 60) (Surah Ghafir is also called Surah Mumin).