Musnad Ahmad 627:11

'Abd al-Rahman and Ibn Ja'far narrated to us, they said: Shu'bah narrated to us, from Muhal ibn Khalifah, 'Abd al-Rahman said: He said: I heard 'Adi ibn Hatim saying: The Messenger of Allah (peace and blessings of Allah be upon him) said: "Fear the Fire, even if it be with half a date. If you do not find [that], then with a good word." And Ibn Ja'far said: "Then with a word."