Sahih Muslim Book 1, Hadith Number 72.

Chapter : Concerning the fact that it is one of the characteristics of Iman that one should like the same thing for one’s brother-in-Islam as one likes for one’s self.

It is arrested on the authority of Anas b. Malik that the Prophet (may peace and blessings be upon him) observed: one amongst you believes (truly) till one likes for his brother or for his neighbour that which he loves for himself.