It was narrated from Anas bin Malik that:
"The Messenger of Allah (ﷺ) said: 'None of you truly believes until he loves for his brother" or he said "for his neighbor, what he loves for himself." (DE)
English reference (DE): Vol. 1, Book 1, Hadith 66 (DE)
Arabic reference (DE): Book 1, Hadith 69 (DE)