مِشْكَاةُ الْمَصَابِيحِ
Mishkat al-Masabih 1052
Prayer
The Congregation and its Excellence - Section 1
عَنِ ابْنِ عُمَرَ قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «صَلَاةُ الْجَمَاعَةِ تَفْضُلُ صَلَاة الْفَذ بِسبع وَعشْرين دَرَجَة»
Ibn ‘Umar reported God’s Messenger as saying, “Prayer said in a congregation is twenty-seven degrees more excellent than prayer said by a single person.” (Bukhari and Muslim.)
Mishkat al-Masabih, 1052مُتَّفق عَلَيْهِ (الألباني)