The Prophet ﷺ said, "Two are better than one, three are better than two, and four are better than three. So hold fast to the community, for Allah will never unite my Ummah except upon guidance."
حدثنا أبو اليمان حدثنا ابن عياش عن البختري بن عبيد بن سلمان عن أبيه
عن النبي ﷺ أنه قال اثنان خير من واحد وثلاث خير من اثنين وأربعة خير من ثلاثة فعليكم بالجماعة فإن الله عز وجل لن يجمع أمتي إلا على هدى
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Its chain is daif, because of Bakhtari bin Salman bin Ubayd and his father. He himself was declared daif by the scholars, while his father is unknown. Haythami likewise declared it daif, 1/177.