Volume 5 · Book 58 · Hadith 127
Narrated Al-Bara: I heard the Prophet saying (or the Prophet said), "None loves the Ansar but a believer, and none hates them but a hypocrite. So Allah will love him who loves them, and He will hate him who hates them."
— Sahih Bukhari, Volume 5, Book 58: Merits of the Helpers in Madinah (Ansaar), Hadith #127