Musnad Abu Ya'la al-Mawsili 3:185

Ubayd Allah ibn Umar al-Qawariri narrated to us, Ja'far ibn Sulayman narrated to us, al-Nadr ibn Humayd al-Kufi narrated to me, from Abu al-Jarud, from al-Harith al-Hamdani, who said: I saw Ali come until he ascended, then he praised Allah and extolled Him, then he said: A decree which Allah decreed upon the tongue of your Prophet, may Allah bless him and grant him peace, the unlettered Prophet: that none loves me except a believer, and none hates me except a hypocrite. And he who fabricates has failed. Al-Nadr said: And Ali said: I am the brother of the Messenger of Allah, may Allah bless him and grant him peace, and his cousin. No one after me shall say it [except a liar].