Al-Adab Al-Mufrad, Hadith 544 ⓘ
Anas reported that the Prophet, may Allah bless him and grant him peace, said, "When two men have love for one another, the better of them is the one who has the strongest love for his companion."
حَدَّثَنَا مُوسَى، قَالَ: حَدَّثَنَا مُبَارَكٌ، قَالَ: حَدَّثَنَا ثَابِتٌ، عَنْ أَنَسٍ قَالَ: قَالَ النَّبِيُّ صلى الله عليه وسلم: مَا تَحَابَّا الرَّجُلاَنِ إِلاَّ كَانَ أَفْضَلُهُمَا أَشَدَّهُمَا حُبًّا لِصَاحِبِهِ.
also referenced under: Book 30, Hadith 7 (In-Book) & Book 30, Hadith 544 (English)