Sunan Ibn Majah 787
سنن ابن ماجه#787SahihIt was narrated from Abu Hurairah that:The Messenger of Allah said: "The prayer in congregation is twenty-five times more virtuous than the prayer of anyone of you on his own
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Al-AlbaniSahih
Muhammad Fouad Abd al-BaqiSahih
Shuaib Al ArnautSahih
Zubair Ali ZaiSahih - Bukhari And Muslim
In-book reference: 4:53