´Muhammad bin Sirin narrated from Abu Hurairah - and I think he (narrated it from the Prophet) who said:` "Love your beloved moderately, perhaps he becomes hated to you someday. And hate whom you hate moderately, perhaps he becomes your beloved someday."
Hadith Referenceسنن ترمذي / كتاب البر والصلة عن رسول الله صلى الله عليه وسلم / 1997