Musnad Ahmad 32:857

Isma'il narrated to us, Sulayman al-Taymi informed us, he said: I heard Anas ibn Malik saying: The Messenger of Allah (peace and blessings of Allah be upon him) said: "Whoever lies about me intentionally, let him occupy his seat in the Fire." He narrated it to us like this twice. And he narrated it to us another time, and he said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "Whoever lies about me intentionally, let him occupy his seat in the Fire."