Sahih al-Bukhari Book 10, Hadith 47
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) .
The reward of the congregational prayer is twenty seven times greater (than that of the prayer offered by a person alone).
The Prophet (ﷺ) said, "The people who get tremendous reward for the prayer are those who are farthest away (from the mosque) and then those who are next farthest and so on. Similarly one who waits to pray with the Imam has greater reward than one who prays and goes to bed. "