Sahih Muslim 112
Sahih Book of The Book of Faith · Hadith 112 of 7,563وَحَدَّثَنَا سَهْلُ بْنُ عُثْمَانَ الْعَسْكَرِيُّ، حَدَّثَنَا يَحْيَى بْنُ زَكَرِيَّاءَ، حَدَّثَنَا سَعْدُ بْنُ طَارِقٍ، قَالَ حَدَّثَنِي سَعْدُ بْنُ عُبَيْدَةَ السُّلَمِيُّ، عَنِ ابْنِ عُمَرَ، عَنِ النَّبِيِّ صلى الله عليه وسلم قَالَ " بُنِيَ الإِسْلاَمُ عَلَى خَمْسٍ عَلَى أَنْ يُعْبَدَ اللَّهُ وَيُكْفَرَ بِمَا دُونَهُ وَإِقَامِ الصَّلاَةِ وَإِيتَاءِ الزَّكَاةِ وَحَجِّ الْبَيْتِ وَصَوْمِ رَمَضَانَ " .
Narrated by ('Abdullah) son of 'Umar
It 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)
References
Sahih Muslim 112
In-book: Book 1, Hadith 20 Source: hadith-api (fawazahmed0)