Hadith 502880
Chapter 8: Prayer in Congregation - كتاب صلاة الجماعة
حَدَّثَنِي يَحْيَى، عَنْ مَالِكٍ، عَنْ نَافِعٍ، عَنْ عَبْدِ اللَّهِ بْنِ عُمَرَ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ " صَلاَةُ الْجَمَاعَةِ تَفْضُلُ صَلاَةَ الْفَذِّ بِسَبْعٍ وَعِشْرِينَ دَرَجَةً " .
Yahya related to me from Malik from Nafi from Abdullah ibn Umar that the Messenger of Allah, may Allah bless him and grant him peace, said, "Prayer in congregation is better than the prayer of a man by himself by twenty-seven degrees."
Reference Muwatta Malik 502880
USC-MSA web (English) reference : Book 8, Hadith 1