Musnad Ahmad 32:1429

Yunus narrated to us, Hammad—meaning Ibn Zayd—narrated to us, from Thabit, from Anas, who said: "I served the Prophet, peace and blessings of Allah be upon him, for ten years. By Allah, he never said 'Uff' to me, nor did he say regarding anything I had done: 'Why did you do such and such?' or 'Why did you not do such and such?'"