كتاب المقدمات
1
The Book of Miscellany
Anas (May Allah bepleased with him) reported:
The Prophet (ﷺ) said, "No one of you shall become a true believer until he desires for his brother what he desires for himself".

[Al-Bukhari and Muslim].

وعن أنس رضي الله عنه صلى الله عليه وسلم قال‏:‏ ‏ "‏ لا يؤمن أحدكم حتى يحب لأخيه ما يحب لنفسه‏"‏ ‏(‏‏(‏متفق عليه‏)‏‏)‏ ‏.‏
Arabic/English book reference : Book 1, Hadith 236