Abu Hurairah (RA) reported: The Messenger of Allah (peace be upon him) said, “By Him in Whose Hand is my life! You will not enter Jannah until you believe, and you will not believe until you love one another. Shall I inform you of something which, if you do, you will love one another? Promote greetings amongst yourselves.”
(Riyad as-Salihin, Book 6, Hadith 4)
