Sahih Muslim 112
صحيح مسلم#112SahihIt is narrated on the authority of ('Abdullah) son of 'Umar, that the Prophet (may peace of Allah be upon him) said:(The superstructure of) al-Islam is raised on five (pillars), i. e. Allah (alone) should be worshipped, and (all other gods) beside Him should be (categorically) denied. Establishment of prayer, the payment of Zakat, Pilgrimage to the House, and the fast of Ramadan (are the other obligatory acts besides the belief in the oneness of Allah and denial of all other gods)
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Every narration in Sahih Muslim is accepted as Sahih (authentic) by the established status of the book.
In-book reference: 1:20