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."
حَدَّثَنَا مُحَمَّدُ بْنُ الْمُثَنَّى، وَابْنُ، بَشَّارٍ قَالاَ حَدَّثَنَا مُحَمَّدُ بْنُ جَعْفَرٍ، حَدَّثَنَا شُعْبَةُ، قَالَ سَمِعْتُ قَتَادَةَ، يُحَدِّثُ عَنْ أَنَسِ بْنِ مَالِكٍ، عَنِ النَّبِيِّ صلى الله عليه وسلم قَالَ " لاَ يُؤْمِنُ أَحَدُكُمْ حَتَّى يُحِبَّ لأَخِيهِ - أَوْ قَالَ لِجَارِهِ - مَا يُحِبُّ لِنَفْسِهِ " .
Muslim
The Book of Faith • Hadith 77