Silsilat al-Ahadith al-Sahihah

It is narrated from Sayyiduna Abu Hurairah (may Allah be pleased with him) that the Prophet (peace and blessings be upon him) said: “Just as there are signs and marks on a road, there are also some signs and marks of Islam. Some of them are: to have faith in Allah and not to associate anyone with Him, to establish prayer, to pay zakat, to fast in Ramadan, to perform Hajj to the House of Allah, to enjoin good, to forbid evil, to greet one’s family when entering the house, and to greet people when passing by them. Whoever falls short in any of these matters, it means that he has abandoned a part of Islam, and whoever abandons all of these things, he has turned his back on Islam (or has cast Islam behind him).”

Sayyiduna Muawiyah bin Haydah (may Allah be pleased with him) says: I said, “O Messenger of Allah! I had sworn as many oaths as the number of my fingers that I would neither come to you nor accept your religion, but now I have come. I am a simple-minded person and I only know a few things that Allah and His Messenger have taught. Now, I ask you by Allah’s name: With what has your Lord sent you?” The Prophet (peace and blessings be upon him) said: “With Islam.” I said, “What are the signs of Islam?” The Prophet (peace and blessings be upon him) said: “That you say: I have submitted my face to Allah and surrendered to Him, and that you establish prayer and pay zakat. Every Muslim is sacred to another Muslim. (In this religion) two brothers help each other, and Allah does not accept any deed of a polytheist after he becomes Muslim until he leaves the polytheists and joins the Muslims.”