From Sahih Muslim (Hadith 75):
Al-Bara reported from the Messenger (may peace and blessing be upon him) that he remarked with regard to the Ansar: "None but the believer loves them, none but the hypocrite hates them. He who loves them loves Allah and he who hates them hates Allah." I (the narrator) said: Did you hear this hadith from al-Bara'? He said: He narrated it to me.
Reference: Muslim 75