Sahih al-Bukhari #649 · Call to Prayers (Adhaan)

Sahih al-BukhariIbn Umar
Sahih al-Bukhari · Book 10 · Call to Prayers (Adhaan)
Sahih al-Bukhari · كتاب 10 · كتاب الأذان
The reward of the congregational prayer is twenty seven times greater (than that of the prayer offered by a person alone)
قَالَ شُعَيْبٌ وَحَدَّثَنِي نَافِعٌ، عَنْ عَبْدِ اللَّهِ بْنِ عُمَرَ، قَالَ تَفْضُلُهَا بِسَبْعٍ وَعِشْرِينَ دَرَجَةً‏.‏
Reference : Sahih al-Bukhari 649In-book reference : Book 10, Hadith 46