ENOfficial
Abu Musa al-Ash‘ari reported God’s Messenger as saying, “Two and over constitute a congregation.” Ibn Majah transmitted it.
Source: sunnah.com
Other translations
Arabic
وَعَنْ أَبِي مُوسَى الْأَشْعَرِيِّ قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «اثْنَانِ فَمَا فَوْقهمَا جمَاعَة» . رَوَاهُ ابْن مَاجَه
sunnah.com