Musannaf Ibn Abi Shayba 24:136

Muhammad ibn Bishr narrated to us, Mis'ar narrated to us, Abu Bakr ibn 'Amr ibn 'Utbah narrated to me, from Jabir ibn Samurah, who said: Sa'd sent me to divide a piece of land between al-Zubayr and Khabbab. They began throwing stones at each other. I returned and informed Sa'd of that. He laughed until he struck his leg and said, "Regarding land the size of this mosque, or he said, 'what does not exceed it,' why did you not turn them away?"