Sufyan b. ‘Abdallah ath-Thaqafi reported that he said, "Messenger of God, say something about Islam concerning which I shall need to ask no one after you are gone.” (A version has "anyone else”.) He said, "Say, ‘I believe in God’, then keep to the straight path.”
Abu Huraira reported that an Arab came to the Prophet and said, "Guide me to a deed by doing which I shall enter paradise.” He said, “Worship God and associate nothing with Him, observe the prescribed prayer, pay the obligatory zakat, and fast during Ramadan.” He replied, "By Him in whose hand my soul is, I shall not add anything to this, or fall short of it.” Then when he turned away the Prophet said, "If anyone wishes to look at a man who will be among the people of paradise, let him look at this man.”
A man of the people of Najd with dishevelled hair came to God’s messenger. We could hear the sound of his voice, but could not understand what he was saying till he came near God’s messenger and we realised that he was asking about Islam. God’s messenger said, “Five times of prayer each day and night.” He asked, “Must I observe any more than them?” He replied, “No, unless you do it voluntarily.” God's messenger said, “And fasting during the month of Ramadan.” He asked, “Must I observe anything else?” He replied, “No, unless you do it voluntarily.” Talha said that God's messenger mentioned the zakat to him, and he asked, “Must I pay anything else?” He replied, “No, unless you do it voluntarily.” He said that the man turned away saying, “I swear by God that I shall not add anything to this or fall short of it.” So God’s messenger said, “The man will prosper if he is speaking the truth.”
Anas reported God’s messenger as saying, "If anyone observes our form of prayer, faces our qibla, and eats what we kill, that one is a Muslim who has protection from God and His messenger; so do not betray God’s protection.”
