Sahih Muslim Book 1, Hadith Number 141.

Chapter : The love of Ansar (helpers) and ‘All (may Allah be pleased with all of them) is (an Ingredient) of Iman and (one of) its signs, and hatred against them is a sign of dissemblance.

Zirr reported: ‘Ali observed: By Him Who split up the seed and created something living, the Apostle(may peace and blessings be upon him) gave me a promise that no one but a believer would love me, and none but a hypocrite would nurse grudge against me.