(31) باب فَضْلِ صَلاَةِ الْفَجْرِ فِي جَمَاعَةٍ
Narrated Salim:
I heard Um Ad-Darda' saying, "Abu Ad-Darda' entered the house in an angry mood. I said to him. 'What makes you angry?' He replied, 'By Allah! I do not find the followers of Muhammad doing those good things (which they used to do before) except the offering of congregational prayer." (This happened in the last days of Abu Ad-Darda' during the rule of `Uthman) .
Reference: Sahih al-Bukhari 650
In-book reference: Book 10, Hadith 47
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 1, Book 11, Hadith 622