8 - It was narrated that Ibn ‘Umar (may Allah be pleased with him) said: The Messenger of Allah (blessings and peace of Allah be upon him) said: “Islam is built on five [pillars]: the testimony that none has the right to be worshipped but Allah and that Muhammad is the Messenger of Allah; establishing prayer; giving zakah; Hajj (pilgrimage); and fasting Ramadan.”.

Commentary : In this important hadith, the Prophet (blessings and peace of Allah be upon him) likened Islam to a well-built structure, and he likened its five pillars to firm foundations that bear the weight of that structure, for the structure cannot stand firmly without them, and other features of Islam are like a completion of that structure. The first of these pillars is the twin testimony of faith (shahadatayn), the testimony that none has the right to be worshipped but Allah and that Muhammad is the Messenger of Allah. These two testimonies form a single pillar, because they are interconnected and one of them cannot be separated from the other. What is meant by the twin testimony of faith is that the individual utters these words, acknowledging and affirming the oneness of Allah and that He alone is deserving of worship, to the exclusion of all others, and acknowledging and affirming that Muhammad ibn ‘Abdillah is the Messenger of Allah, believing that in his heart, and acting in accordance with the meanings thereof. This is the testimony that will benefit a person in the hereafter, so that he will attain Paradise and be saved from Hell.
The second pillar is establishing the prayer, which means regularly performing the five obligatory prayers every day and night – namely Fajr, Zuhr, ‘Asr, Maghrib and ‘Isha’ – performing the prayers on time, with all their conditions, essential parts and obligatory actions.
The third pillar is giving zakah, which is an obligatory, financial act of worship, to be given on every type of wealth that meets the minimum threshold, as defined in Islamic teachings, when one full lunar (or Hijri) year has passed since acquiring that wealth, giving one quarter of one tenth. One should also give zakah on an‘am animals [camels, cattle and sheep] and other livestock; zakah on crops, fruits, and trade goods; and zakah on rikaz, which is buried treasure that is brought out of the earth and, it was said, minerals and metals, on the basis of their minimum threshold (nisab), to be given at the time at which their zakah becomes due. Giving zakah in the proper manner to those who are entitled to it brings increased blessing (barakah) to wealth, and brings great reward in the hereafter, whereas being stingy and withholding it from those who are entitled to it brings bad consequences in this world and the hereafter, as has been explained in many texts of the Qur’an and Sunnah. Zakah is to be given to those who are entitled to it, who are mentioned in the verse: {Zakah expenditures are only for the poor and for the needy and for those employed to collect [zakah] and for bringing hearts together [for Islam] and for freeing captives [or slaves] and for those in debt and for the cause of Allah and for the [stranded] traveler - an obligation [imposed] by Allah. And Allah is Knowing and Wise} [al-Tawbah 9:60].
The fourth pillar is Hajj, which means going to the holy places to perform the rituals as an act of worship to Allah (may He be glorified and exalted), once in a lifetime. In order for hajj to be obligatory, one must be physically and financially able to do it.
The fifth and last pillar is fasting Ramadan, which is a physical act of worship. The word siyam (fasting) means refraining, with the intention of worship, from food, drink, sexual activity and other things that break the fast, from the break of dawn until the sun sets.
This hadith indicates that the pillars of Islam may be divided into four categories: that which is verbal and in the heart, namely the twin declaration of faith, which must be uttered on the tongue and believed in the heart; that which involves a physical action, namely prayer and fasting; that which is purely financial, namely zakah; and that which is both physical and financial, namely Hajj..