Sayyiduna Jabir bin Samurah (may Allah be pleased with him) said: The Prophet (peace and blessings be upon him) came to us while we were split into separate circles, and he (peace and blessings be upon him) said: "What is the matter? I see you scattered in separate groups."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الجمعة / 5904
Amr bin Shu'ayb narrates from his father, and he from his grandfather (may Allah be pleased with him), that the Prophet (peace and blessings be upon him) "forbade sitting in circles on Friday before the prayer."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الجمعة / 5905