(1) باب وُجُوبِ الصِّيَامِ
It was narrated that Abu Hurairah said:
"While the Prophet was with his Companions a man from among the desert people came and said: 'Which of you is the son of 'Abdul-Muttalib?' They said: 'This Anghar man who is reclining on a pillow.' (One of the narrators) Hamzah said: "Amghar means white with a reddish complexion.'- The man said: 'I am going to ask you questions and I will be harsh in asking.' He said: 'ask whatever you like.' He said: 'I ask you by your Lord and the Lord of those who came before you, and the Lord of those who will come after you; has Allah sent you?' He said: 'By Allah, yes.' He said: 'I adjure you by Him, has Allah commanded you to offer five prayers each day and night?' He said: 'By Allah, yes.; He said: 'I adjure you by Him, has Allah commanded you to take from the wealth of our rich and give it to our poor?' he said: 'By Allah, yes He said: 'I adjure you by Allah, has Allah commanded you to fast this month out of the twelve months?' He said: 'By Allah, yes.' He said: 'I adjure you by Him, has Allah commanded you to go on pilgrimage to this House, where can afford it?' He said: 'By Allah yes.' He said: 'I belive, and I am Dimam bin Thalabah."'
Reference: Sunan an-Nasa'i 2094
In-book reference: Book 22, Hadith 5
English translation: Vol. 3, Book 22, Hadith 2096