First of all, we would like to note that the words ‘Ma`lum Min Ad-Din Bid-Darurah’ stand as an Arabic term referring to all well-established principles of Islam. For example, considering adultery as prohibited is ‘Ma`lum Min Ad-Din Bid-Darurah’, since all people know it well and it’s universally established as an evil deed.
The eminent Muslim scholar Sheikh Yusuf Al-Qaradawi states the following: “Veteran Muslim scholars define the words ‘Ma`lum Min Ad-Din Bid-Darurah as a term referring to Islamic ordinances that are known to all people of all walks of life, specialists or laymen. These ordinances are beyond the bounds of argument, and do not call for any special acumen for a person to know them, for they have become well-established facts throughout history.
These ordinances, in effect, serve as the bedrock or cornerstone representing the unity of Muslim Ummah intellectually, emotionally and scientifically. In consequence, such ordinances are utterly incontrovertible. Allah Almighty, therefore, did by no means reveal His ordinances in the Glorious Qur’an or on His Messenger, peace and blessings of Allah be upon him, to be used as a means of seeking blessing or to be emblazoned across the walls; rather, they are revealed for the very aim of being put into force, to regulate the lives of people according to the commands and the laws set for them by their Lord.
It is incumbent upon every true Muslims, who testify that there is no god but Allah, Muhammad is Messenger of Allah, accepts Islam as a religion, to obey the commands of Allah and His Messenger devotedly. Before these ordinances, a true Muslim says: “No sooner said, than done. We listen and obey our Lord!”
Dr. `Ali Jum`ah, professor of the Principles of Islamic Jurisprudence at Al-Azhar university, adds: The term ‘Ma`lum Min Ad-Din Bid-Darurah’ is used to refer to the well-established and fixed ordinances of Islamic Shari`ah. Such ordinances represent the cornerstone of Islam and the entity of religion.
For example, all Muslims agree on the obligatory nature of prayer, Zakah, pilgrimage and fasting (during the month of Ramadan). In the same sense, all Muslims agree on the permissibility of the lawful sale; the same applies to marriage. Also there is some sort of consensus among people as regards specific penalties pertaining to certain crimes or acts of transgression and that each crime requires certain punishment in Shari`ah. It is also agreed upon that adultery, eating pork, eating dead animals, dealing usury and drinking wine are all prohibited acts. All these matters are included in the term ‘Ma`lum Min Ad-Din Bid-Darurah’. Regarding those matters, ignorance cannot be accepted or considered as a valid excuse. Denying such ordinances place the person outside the fold of Islam.”
Here, it is also useful to cite for you the following from ‘Al-Qawa`id Az-Zahabiyah’ (The Brilliant Rules) by the great Companion, `Abdullah ibn `Abbas:
“It is not acceptable to deny any of the well-established ordinances of Islam referred to as ‘Ma`lum Min Ad-Din Bid-Darurah’. These ordinances include the necessity of believing in Allah, His Angels, Divinely-revealed Books, the Last Day, Divine Predestination, the obligatory nature of prayer, Zakah, pilgrimage, the prohibition of wine, adultery and usury. All such things are, in no way, subject to disagreement or controversy.”
Almighty Allah knows best.