عن أبي كريمة المقداد بن معد يكرب رضي الله عنه عن النبي صلى الله عليه وسلم قال: «إِذَا أَحَبَّ الرَّجُلُ أَخَاهُ، فَلْيُخْبِرْهُ أَنَّهُ يُحِبُّهُ».
[صحيح] - [رواه أبو داود والترمذي والنسائي في السنن الكبرى وأحمد]
Abu Karīmah al-Miqdād ibn Ma‘dikarib (may Allah be pleased with him) reported that the Prophet (may Allah's peace and blessings be upon him) said: "When a man loves his brother, he should tell him that he loves him."
Sahih/Authentic. - [At-Tirmidhi]
Many Hadīths promote mutual love for the sake of Allah, the Almighty, and inform of its reward. This Hadīth promotes a profound meaning that will greatly impact the believers' relationship with one another as well as spread love. A person should inform his brother that he loves him. This will preserve the structure of the Muslim society against factors of disintegration and dissolution, by way of spreading love among individuals in the Islamic society, and strengthening the societal bonds by means of Muslim brotherliness. This is achievable through observing means of love, the example of which is telling each other that they love each other for the sake of Allah, the Almighty.