Not graded
Al-Adab al-Mufrad 544
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.
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."
Cited in Al-Adab al-Mufrad (No. 544).