‏الصلاة : Hadeeth No:1366 Ibn 'Umar reported Allaah's Prophet (sallAllaahu alayhi wa sallam) as saying: The prayer of a person in congregation is twenty-seven times in excess to the prayer said alone....

‏القدر : Hadeeth No:6415 Abu Huraira reported a hadith like this through another chain of transmitters....