Musnad Ahmad 626:107

Waki’ narrated to us, Sufyan narrated to us, he said: And ‘Abd al-Rahman narrated to us, from Sufyan, from Habib, from Maymun ibn Abi Shabib, from al-Mughirah ibn Shu’bah, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "Whoever narrates a hadith while he sees that it is a lie, then he is one of the two liars." And ‘Abd al-Rahman said: "Then he is one of the two great liars."