The Prophet ﷺ said, "Prayer in congregation surpasses the prayer of a man alone by twenty-seven degrees."
حدثنا يحيى عن عبيد الله حدثني نافع
عن النبي ﷺ قال الصلاة في الجميع تزيد على صلاة الرجل وحده سبعا وعشرين
Its isnad is sahih, and Bukhari and Muslim narrated it, as in Muntaqa 1349. Something similar in meaning has already passed from the hadith of Ibn Masud several times, the last being 4433.