The word is most often found in the Qur'anic exhortation: امر بالمعروف و نهى عن المنكر "Amr bil Ma'ruf wa Nahy an al Munkar", often translated as "Enjoin the good and forbid the wrong".
Maʿrūf and munkar are widely discussed because of the duties the Quran imposes on believers through these concepts.
In today's religious expression, maʿrūf is sunnah (this concept was not different from custom in the beginning[4][5]), munkar is meant as bid'a.
[6] Pre-modern Islamic literature describes pious Muslims (usually scholars) taking action to forbid wrong by destroying forbidden objects, particularly liquor and musical instruments.
[7] In the contemporary Muslim world, various state or parastatal bodies (often with phrases like the "Promotion of Virtue and the Prevention of Vice" in their titles) have appeared in Iran, Saudi Arabia,[8] Nigeria, Sudan, Malaysia, etc., at various times and with various levels of power.