عَنْ أَبِي هُرَيْرَةَ رَضِيَ اللَّهُ عَنْهُ أَنَّ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ قَالَ ((إِنَّ اللَّهَ اصْطَفَى مِنَ الْكَلَامِ أَرْبَعًا سُبْحَانَ اللَّهِ وَالْحَمْدُ لِلَّهِ وَلَا إِلَهَ إِلَّا اللَّهُ وَاللَّهُ أَكْبَرُ فَمَنْ قَالَ سُبْحَانَ اللَّهِ كَتَبَ اللَّهُ لَهُ عِشْرِينَ حَسَنَةً أَوْ حَطَّ عَنْهُ عِشْرِينَ سَيِّئَةً وَمَنْ قَالَ اللَّهُ أَكْبَرُ فَمِثْلُ ذَلِكَ وَمَنْ قَالَ لَا إِلَهَ إِلَّا اللَّهُ فَمِثْلُ ذَلِكَ وَمَنْ قَالَ الْحَمْدُ لِلَّهِ رَبِّ الْعَالَمِينَ مِنْ قِبَلِ نَفْسِهِ كُتِبَ لَهُ ثَلَاثُونَ حَسَنَةً أَوْ حُطَّتْ عَنْهُ ثَلَاثُونَ سَيِّئَةً))
It is narrated from Sayyiduna Abu Hurairah (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: Verily, Allah Almighty has chosen these four words from speech: Subhan Allah, Alhamdulillah, La ilaha illallah, and Allahu Akbar. So whoever says Subhan Allah, Allah writes twenty good deeds for him or erases twenty bad deeds; whoever says Allahu Akbar will have the same reward; whoever says La ilaha illallah will have the same reward; and whoever says from himself Alhamdulillahi Rabbil 'Alamin, thirty good deeds will be written for him and thirty bad deeds will be erased.