Musnad Ahmad 3:109

'Abd al-Kabir ibn 'Abd al-Majid Abu Bakr al-Hanafi narrated to us, 'Abd al-Hamid ibn Ja'far narrated to us, from his father, from Mahmud ibn Labid, from 'Uthman ibn 'Affan, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "Whoever intentionally lies about me, let him take his seat in the Fire."