Al-Adab Al-Mufrad, Hadith 542 ⓘ
Al-Miqdam ibn Ma'dikarib reported that the Prophet, may Allah bless him and grant him peace, said, "When one of you has love for his brother, he should inform him that he loves him."
حَدَّثَنَا مُسَدَّدٌ، قَالَ: حَدَّثَنَا يَحْيَى بْنُ سَعِيدٍ، عَنْ ثَوْرٍ قَالَ: حَدَّثَنِي حَبِيبُ بْنُ عُبَيْدٍ، عَنِ الْمِقْدَامِ بْنِ مَعْدِي كَرِبَ، وَكَانَ قَدْ أَدْرَكَهُ، قَالَ: قَالَ النَّبِيُّ صلى الله عليه وسلم: إِذَا أَحَبَّ أَحَدُكُمْ أَخَاهُ فَلْيُعْلِمْهُ أَنَّهُ أَحَبَّهُ.
also referenced under: Book 30, Hadith 5 (In-Book) & Book 30, Hadith 542 (English)