Narrated Abu Sa'eed Al-Khudri:
"We, the people of the Ansar, used to recognize the hypocrites, by their hatred for 'Ali bin Abi Talib." (JA)
English reference (JA): Vol. 1, Book 46, Hadith 3717 (JA)
Arabic reference (JA): Book 49, Hadith 4082 (JA)