Yahya related to me from Malik from Ibn Shihab from Said ibn al-Musayyab from Abu Hurayra that the Messenger of Allah, may Allah blesshim and grant him peace, said, "Prayer in congregation is better thanthe prayer of one of you on his own by twenty-five parts."
App reference: Book 8, Hadith 2
USC-MSA web (English) reference: Book 8, Hadith 2
Arabic reference: Book 8, Hadith 289