A condition placed on belief itself
Short, and phrased as an exclusion.
لا يُؤْمِنُ أَحَدُكُمْ حَتَّى يُحِبَّ لأَخِيهِ مَا يُحِبُّ لِنَفْسِهِ
None of you believes until he loves for his brother what he loves for himself.
The full narration
Narrated Anas: The Prophet (ﷺ) said, "None of you will have faith till he wishes for his (Muslim) brother what he likes for himself
Source
Ṣaḥīḥ al-Bukhārī · 13
Ṣaḥīḥ
- Agreed upon as authentic (al-Bukhārī / Muslim)