Musnad Ahmad 32:821

Hajjaj narrated to us, Shu'bah informed us, and Hashim said: Shu'bah narrated to us, from 'Attab—and Hashim said: the freed slave of Banu Hurmuz—he said: I heard Anas ibn Malik saying: "Were it not that I fear I might err, I would have narrated to you things I heard from the Messenger of Allah, may Allah bless him and grant him peace." However, he said: "Whoever lies about me intentionally, let him take his seat in the Fire." Hashim said: "The Messenger of Allah, may Allah bless him and grant him peace, said it," or "I heard it from the Messenger of Allah, may Allah bless him and grant him peace."