Musnad Ahmad 32:491

Zayd ibn al-Hubab narrated to us, Husayn ibn Waqid narrated to me, Thabit al-Bunani narrated to me, Anas ibn Malik narrated to me, that the Messenger of Allah (peace and blessings of Allah be upon him) entrusted a man to Hafsa bint Umar and said to her: "Keep watch over him." He said: Hafsa became heedless, and the man went away. The Messenger of Allah (peace and blessings of Allah be upon him) entered and said: "O Hafsa, what did the man do?" She said: I became heedless of him, O Messenger of Allah. He went out, and the Messenger of Allah (peace and blessings of Allah be upon him) said: "May Allah cut off your hand." She raised her hands like this, and the Messenger of Allah (peace and blessings of Allah be upon him) entered and said: "What is the matter with you, O Hafsa?" She said: O Messenger of Allah, you said such and such. He said to her: "Lower your hands, for I have asked Allah: whichever person from my nation I have invoked Allah against, that He make it an expiation for him."