حَدَّثَنَا أَبُو كُرَيْبٍ، حَدَّثَنَا أَبُو مُعَاوِيَةَ، عَنْ هِلاَلِ بْنِ مَيْمُونٍ، عَنْ عَطَاءِ بْنِ يَزِيدَ، عَنْ أَبِي سَعِيدٍ الْخُدْرِيِّ، قَالَ قَالَ رَسُولُ اللَّهِ ـ صلى الله عليه وسلم ـ صَلاَةُ الرَّجُلِ فِي جَمَاعَةٍ تَزِيدُ عَلَى صَلاَتِهِ فِي بَيْتِهِ خَمْسًا وَعِشْرِينَ دَرَجَةً "
It was narrated that Abu Sa'eed Al-Khudri said:
"The Messenger of Allah said: 'the prayer of a man in congregation is twenty-five levels higher than his prayer in his home.'"
Reference: Sunan Ibn Majah 788
In-book : Book 4, Hadith 54
English translation : Vol. 1, Book 4, Hadith 788