‘Umar ibn al-Khattāb (may Allah be pleased with him) reported: The Messenger of Allah (may Allah’s peace and blessings be upon him) said: "Verily, the reward of deeds depends on the intention, and a person will be rewarded according to what he intended. So, he whose migration is for the sake of Allah and His Messenger, then his migration is for the sake of Allah and His Messenger, and he whose migration is to achieve some worldly gain or take some woman in marriage, then his migration is for what he migrated for." In a version by Al-Bukhāri: "Verily, the reward of deeds depends on the intentions, and each person will be rewarded according to what he intended."

‘Ā’ishah (may Allah be pleased with her) reported that the Messenger of Allah (may Allah's peace and blessings be upon him) said: "Whoever introduces into this matter of ours (Islam) something that does not belong to it shall have it rejected." [Agreed upon] A narration by Muslim reads: "Whoever does something that is not in accordance with this matter of ours shall have it rejected."

‘Umar ibn al-Khattāb (may Allah be pleased with him) reported: One day, we were sitting with the Messenger of Allah (may Allah's peace and blessings be upon him) when there appeared before us a man dressed in extremely white clothes and had very black hair. No traces of travel were visible on him, and none of us knew him. He came in and sat down opposite the Prophet (may Allah's peace and blessings be upon him), rested his knees against his, and placed the palms of his hands on his (the Prophet's) thighs. He said: "O Muhammad, tell me about Islam." The Messenger of Allah (may Allah's peace and blessings be upon him) said: "Islam is to testify that there is no god but Allah and that Muhammad is the Messenger of Allah, to establish prayer, to pay Zakah, to fast Ramadan, and to perform Hajj to the House if you are able to find a way thereto." He said: "You have spoken the truth." We wondered how he asked him and affirmed his truthfulness. Then, he said: "Tell me about Imān (faith)." He said: "It is to believe in Allah, His angels, His books, His messengers, and the Last Day, and believe in the divine decree, the pleasant and unpleasant aspects thereof." Then, he said: "You have spoken the truth." Then, he said: "Tell me about ihsān." He said: "It is to worship Allah as if you see Him, for if you do not see Him, He sees you." He said: "Tell me about the Hour." He said: "The one questioned about it knows no more than the questioner." He said: "Then, tell me about its signs." He said: "The slave girl will give birth to her mistress, and you will see the barefoot, naked, and destitute herdsmen competing in constructing lofty buildings." Then, he departed. I stayed for a while, and then he said to me: "O 'Umar, do you know who the questioner was?" I said: "Allah and His Messenger know best." He said: "He was Jibrīl (Gabriel). He came to teach you your religion."

‘Abdullah ibn ‘Umar (may Allah be pleased with him and his father) reported that the Messenger of Allah (may Allah's peace and blessings be upon him) said: "Islam is built on five: testifying that there is no god but Allah and that Muhammad is His slave and Messenger, establishing prayer, giving Zakah, performing Hajj to the (Sacred) House, and fasting Ramadān."

Mu‘ādh (may Allah be pleased with him) reported: I was riding behind the Prophet (may Allah’s peace and blessings be upon him) on a donkey called ‘Ufayr. The Prophet (may Allah’s peace and blessings be upon him) asked: "O Mu‘ādh, do you know what Allah's right upon His servants is, and what the right of His servants upon Him is?" I replied: "Allah and His Messenger know best." He said: "Allah's right upon His servants is that they should worship Him and associate no partners with Him. And the right of the servants upon Allah is that He should not punish whoever associates no partners with Him." I said: "O Messenger of Allah, should I not inform the people of this good news?" He said: "Do not inform them of it, lest they depend on it solely."

Anas ibn Mālik (may Allah be pleased with him) reported: As the Prophet (may Allah's peace and blessings be upon him) was riding a mount with Mu‘ādh behind him, he said: "O Mu‘ādh ibn Jabal!" He replied: "Here I am at your service, O Messenger of Allah." He again said: "O Mu‘ādh!" Mu‘ādh replied: "Here I am at your service, O Messenger of Allah." This was said three times. Then, the Prophet (may Allah's peace and blessings be upon him) said: "There is no one who bears witness that there is no god but Allah and that Muhammad is His slave and Messenger, sincerely from his heart, except that Allah will make him forbidden to Hellfire." He said: "O Messenger of Allah, should I not inform the people of that so that they may rejoice?" He replied: "Then they would rely on this alone." Mu‘ādh narrated this Hadīth at the time of his death to avoid the sin of concealing knowledge.

Tāriq ibn Ashīm al-Ashja‘i (may Allah be pleased with him) reported: I heard the Messenger of Allah (may Allah’s peace and blessings be upon him) say: "Whoever says 'lā ilāha illa Allah (there is no god but Allah)' and disbelieves in everything worshiped besides Allah, his property and blood becomes inviolable, and his reckoning will be with Allah."

Jābir (may Allah be pleased with him) reported: A man came to the Prophet (may Allah’s peace and blessings be upon him) and said: "O Messenger of Allah, what are the two imperatives?" He said: "Whoever dies while not associating anything with Allah will enter Paradise, and whoever dies while associating anything with Allah will enter Hellfire."

‘Abdullah ibn Mas‘ūd (may Allah be pleased with him) reported: "The Prophet (may Allah's peace and blessings be upon him) said something and I said another thing. The Prophet (may Allah's peace and blessings be upon him) said: 'Whoever dies while invoking besides Allah another equal will enter Hellfire.' And I say: 'Whoever dies while not invoking besides Allah another equal will enter Paradise.'"

Ibn ‘Abbās (may Allah be pleased with him) reported: The Messenger of Allah (may Allah’s peace and blessings be upon him) said to Mu‘ādh ibn Jabal as he was sending him to Yemen: "You will come to a people of the Scripture. When you reach them, invite them to testify that none is worthy of worship except Allah and that Muhammad is the Messenger of Allah. If they obey you in that, tell them that Allah has enjoined on them five prayers every day and night. If they obey you in that, tell them that Allah has enjoined Zakah on them, to be taken from the rich amongst them and given to the poor amongst them. If they obey you in that, beware of taking their best properties; and fear the invocation of an oppressed person, for there is no barrier between his invocation and Allah.”

Abu Hurayrah (may Allah be pleased with him) reported: It was said: "O Messenger of Allah, who will be the happiest of people to receive your intercession on the Day of Judgment?" The Messenger of Allah (may Allah's peace and blessings be upon him) said: "I thought no one would ask me about this Hadīth before you, O Abu Hurayrah, given the keenness I have seen from you regarding the Hadīths. The happiest of people to receive my intercession on the Day of Judgment is the one who says, 'there is no god but Allah' sincerely from his heart or his soul."

Abu Hurayrah (may Allah be pleased with him) reported: The Messenger of Allah (may Allah's peace and blessings be upon him) said: "Faith has over seventy branches - or over sixty branches - the most excellent of which is the declaration that 'lā ilāha illa Allah (there is no god but Allah)', and the lowest of which is the removal of what is harmful from the way; and modesty is a branch of faith."