Sayyiduna Ibn 'Umar (RadhiAllaho anho) narrates
that Rasulullah (Sallallahu Alaihi Wasallam) said:
Islām is based on (the following) five (basic) principles:
1. To testify that none has the right to be worshipped but
Allāh Subhanahu Wa Ta'ala and
Muhammad Sala-llahu Alahi Wa Salam
is Allah's Messenger.
2. To offer the (compulsory congregational) prayers
dutifully and perfectly.
3. To pay Zakat (i.e. obligatory charity) .
4. To perform Hajj. (i.e. Pilgrimage to Makkah)
5. To observe fast during the month of Ramadan.
{Sahih Al-Bukhari, Sahih Muslim.}