Musnad Abu Ya'la al-Mawsili 117:105

Ubayd Allah ibn Umar narrated to us, Hammad ibn Zayd narrated to us, Thabit narrated to us, from Anas ibn Malik, who said: Fatima said to me, "O Anas, how were your souls content to cast earth upon the Messenger of Allah, may Allah bless him and grant him peace?"