It is narrated from Ziyad bin Naeem Hadhrami, may Allah have mercy on him, that the Messenger of Allah, peace and blessings be upon him, said: "There are four things which Allah Almighty has made obligatory in Islam. If a servant performs three of them, they will not suffice him until he fulfills all of them. These four matters are: prayer, zakat, fasting in Ramadan, and pilgrimage to the House of Allah (Hajj)."

Sayyiduna Ali (may Allah be pleased with him) narrates that the Messenger of Allah (peace and blessings be upon him) said:“No servant can be a believer until he believes in these four things: bearing witness that there is no deity worthy of worship except Allah and that I am the Messenger of Allah, that He has sent me with the truth, belief in resurrection after death, and belief in destiny.”

(Second chain) The Messenger of Allah, peace and blessings be upon him, said: "No servant will be a believer until he believes in these four things: he believes in Allah Almighty, and in that Allah Almighty has sent me with the truth, he believes in resurrection after death, and he believes in destiny, whether it is good or bad."

Sayyiduna Ibn Khassasiyyah Sudusi (may Allah be pleased with him) says: I came to the Messenger of Allah (peace and blessings be upon him) to pledge allegiance to him. The Messenger of Allah (peace and blessings be upon him) placed these conditions upon me:“To bear witness that there is no deity worthy of worship except Allah and that Muhammad (peace and blessings be upon him) is His servant and Messenger, to establish prayer, to pay zakat, to perform the obligatory Hajj, to fast in Ramadan, and to strive in the way of Allah.”I said:“O Messenger of Allah! As for these two things—jihad and zakat—I do not have the strength for them, because people say about jihad that whoever turns his back from there returns with the wrath of Allah, so I fear that perhaps my soul may become anxious in the battlefield and may begin to dislike death. As for zakat, by Allah, I have only a few goats and ten camels; these are the milk-giving and riding animals for my family.”Upon hearing this, the Messenger of Allah (peace and blessings be upon him) closed his hand, moved it, and said:“If there is neither jihad nor zakat, then how will you enter Paradise?”I said:“O Messenger of Allah! Fine, I pledge allegiance to you,”then I pledged allegiance to him on all these matters.

It is narrated from Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) that when the Messenger of Allah (peace and blessings be upon him) sent Sayyiduna Mu’adh (may Allah be pleased with him) towards Yemen, he said to him:“You are going to a people of the Book, so first invite them to testify that there is no true deity except Allah and that I am the Messenger of Allah. If they obey you in this matter, then inform them that Allah the Exalted has made five prayers obligatory upon them in every day and night. If they accept this as well, then teach them that Allah has made zakat obligatory upon their wealth, to be taken from their rich and distributed among their poor. If they agree to this too, then beware of taking the best of their wealth, and beware of the supplication of the oppressed, for there is no barrier between it and Allah the Exalted.”

It is narrated from Sayyiduna Abu Hurairah, may Allah be pleased with him, that the Messenger of Allah, peace and blessings be upon him, said: "Faith has sixty-four branches; the highest and most exalted of them is to say «لاَ إِلَهَ إِلَّا اللَّهُ» , and the lowest branch is to remove something harmful from the path."

It is also narrated from Sayyiduna Abu Hurairah, may Allah be pleased with him, that the Messenger of Allah, peace and blessings be upon him, said: "Faith has seventy-five or seventy-six branches, the most excellent of which is «لاَ إِلَهَ إِلَّا اللَّهُ» and the lowest is removing something harmful from the road, and modesty is also a branch of faith."

Sayyiduna Nawwas bin Sam'an Ansari (may Allah be pleased with him) narrates that the Messenger of Allah (peace and blessings be upon him) said: "Allah Almighty has given an example: there is a straight path, on both sides of this path are two walls, in which there are open doors, and curtains are hanging over the doors. At the entrance of the path, a caller is saying: O people! Enter all of you into the path and do not deviate from it. And when someone wants to open any of the doors, a caller from the middle of the path calls out: You will be ruined, do not open it; if you open it, you will enter into it. (The explanation of this example is that) the path is Islam, and the walls are the boundaries set by Allah Almighty, and the open doors are the things forbidden by Allah Almighty, and the caller at the entrance of the path is the Book of Allah Almighty, and the caller in the middle of the path is the admonisher from Allah Almighty present in the heart of every Muslim."

(Second Chain) Sayyiduna Nawwas (may Allah be pleased with him) reports: The Messenger of Allah (peace and blessings be upon him) said to me: "Indeed, Allah the Exalted has given an example: there is a straight path, on both sides of which are walls, and in them are open doors upon which curtains are hanging, and there is a caller at the head of the path, and a caller above the servant. And Allah the Exalted calls towards the abode of peace, and He guides whom He wills to the straight path. The doors on both sides of the path are the limits set by Allah the Exalted; as long as a person does not tear Allah's curtain, he does not enter into His limits. And the caller who calls from above is the admonisher from Allah the Exalted."

It is narrated from Sayyiduna Sufyan bin Abdullah Thaqafi (may Allah be pleased with him), he says: I said, "O Messenger of Allah! Tell me something about Islam such that after you (Abu Muawiyah has narrated the words 'after you'), there remains no need to ask anyone else about it." The Prophet (peace and blessings be upon him) said: "Say, 'I believe in Allah,' and then remain steadfast upon it."