(17) باب الدَّلِيلِ عَلَى أَنَّ مِنْ خِصَالِ الإِيمَانِ أَنْ يُحِبَّ لأَخِيهِ الْمُسْلِمِ مَا يُحِبُّ لِنَفْسِه مِنَ الْخَيْرِ
It is narrated on the authority of Anas b. Malik that the Prophet (may peace and blessings be upon him) observed:
"None amongst you believes (truly) until he loves for his brother" - or he said "for his neighbour" - "that which he loves for himself."
Reference: Sahih Muslim 45 a
In-book reference: Book 1, Hadith 77
USC-MSA web (English) reference(deprecated numbering scheme): Book 1, Hadith 72