Sayyiduna Bilal al-Absi (may Allah be pleased with him) says that the Messenger of Allah (peace and blessings be upon him) said: "Three things are included in the protected reserve: the water of the well, the stable of horses, and the gathering circle of people."
This is mursal.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب إحياء الموات / 11838