Anas ibn Malik reported: The Prophet, peace and blessings be upon him, said,

عَنْ أَنَسٍ عَنِ النَّبِيِّ صلى الله عليه وسلم قَالَ لا يُؤْمِنُ أَحَدُكُمْ حَتَّى يُحِبَّ لأَخِيهِ مَا يُحِبُّ لِنَفْسِهِ

“None of you will have faith until he loves for his brother what he loves for himself.”

Source: Sahih Bukhari & Sahih Muslim