Sahih Muslim 12a

Amr ibn Muhammad ibn Bukayr al-Naqid narrated to me; Hashim ibn al-Qasim Abu al-Nadr narrated to us; Sulayman ibn al-Mughirah narrated to us, from Thabit, from Anas ibn Malik, who said: We were forbidden to ask the Messenger of Allah (peace and blessings be upon him) about anything. We used to be pleased when an intelligent man from among the desert people came and asked him while we listened. A man from the desert people came and said, ‘Muhammad, your messenger came to us and claimed to us that you claim Allah sent you.’ He said, ‘He spoke truthfully.’ He said, ‘Who created the heaven?’ He said, ‘Allah.’ He said, ‘Who created the earth?’ He said, ‘Allah.’ He said, ‘Who raised these mountains and placed in them what is in them?’ He said, ‘Allah.’ He said, ‘By the One who created the heaven, created the earth, and raised these mountains, did Allah send you?’ He said, ‘Yes.’ He said, ‘And your messenger claimed that we are required to perform five prayers in our day and night.’ He said, ‘He spoke truthfully.’ He said, ‘By the One who sent you, did Allah command you to do this?’ He said, ‘Yes.’ He said, ‘And your messenger claimed that we are required to pay zakat from our wealth.’ He said, ‘He spoke truthfully.’ He said, ‘By the One who sent you, did Allah command you to do this?’ He said, ‘Yes.’ He said, ‘And your messenger claimed that we are required to fast the month of Ramadan in our year.’ He said, ‘He spoke truthfully.’ He said, ‘By the One who sent you, did He command you to do this?’ He said, ‘Yes.’ He said, ‘And your messenger claimed that we are required to make Pilgrimage to the House, whoever is able to find a way to it.’ He said, ‘He spoke truthfully.’ Then he turned away and said, ‘By the One who sent you with the truth, I will neither add to these nor subtract from them.’ The Prophet (peace and blessings be upon him) said, ‘If he is truthful, he will surely enter Paradise.’