Sahih Muslim Book - 5, Hadith - 1358

حَدَّثَنَا زُهَيْرُ بْنُ حَرْبٍ حَدَّثَنَا إِسْمَاعِيلُ ابْنُ عُلَيَّةَ أَخْبَرَنِى الْحَجَّاجُ بْنُ أَبِى عُثْمَانَ عَنْ أَبِى الزُّبَيْرِ عَنْ عَوْنِ بْنِ عَبْدِ اللَّهِ بْنِ عُتْبَةَ عَنِ ابْنِ عُمَرَ قَالَ بَيْنَمَا نَحْنُ نُصَلِّى مَعَ رَسُولِ اللَّهِ -صلى الله عليه وسلم- إِذْ قَالَ رَجُلٌ مِنَ الْقَوْمِ اللَّهُ أَكْبَرُ كَبِيرًا وَالْحَمْدُ لِلَّهِ كَثِيرًا وَسُبْحَانَ اللَّهِ بُكْرَةً وَأَصِيلاً. فَقَالَ رَسُولُ اللَّهِ -صلى الله عليه وسلم- « مَنِ الْقَائِلُ كَلِمَةَ كَذَا وَكَذَا ». قَالَ رَجُلٌ مِنَ الْقَوْمِ أَنَا يَا رَسُولَ اللَّهِ. قَالَ « عَجِبْتُ لَهَا فُتِحَتْ لَهَا أَبْوَابُ السَّمَاءِ ». قَالَ ابْنُ عُمَرَ فَمَا تَرَكْتُهُنَّ مُنْذُ سَمِعْتُ رَسُولَ اللَّهِ -صلى الله عليه وسلم- يَقُولُ ذَلِكَ.

It was narrated that Ibn 'Umar said: "While we were praying with the Messenger of Allah (s.a.w), a man among the people said: 'Allahu akbaru kabiran, wal-hamdulillahi kathiran, wa subhan Allahi bukaratan wa asila (Allah is most great, much praise be to Allah, glory be to Allah morning and evening).' The Messenger of Allah (s.a.w) said: 'Who said such and such?' A man said: 'I did, O Messenger of Allah.' He said: 'I was impressed by it, for the gates of heaven were opened for it."' Ibn 'Umar said: "I never stopped saying them since I heard the Messenger of Allah (s.a.w) say that."