Enjoining good and forbidding wrong (Arabic: ٱلْأَمْرُ بِٱلْمَعْرُوفِ وَٱلنَّهْيُ عَنِ ٱلْمُنْكَرِ, romanized: al-amru bi-l-maʿrūfi wa-n-nahyu ʿani-l-munkari) are two important duties imposed by God in Islam as revealed in the Quran and Hadith.

This expression is the base of the classical Islamic institution of ḥisba, the individual or collective duty (depending on the Islamic school of law) to intervene and enforce Islamic law. It forms a central part of the Islamic doctrine for Muslims. The injunctions also constitute two of the ten Ancillaries of the Faith of Twelver Shi'ism.

Pre-modern Islamic literature describes pious Muslims (usually scholars) taking action to forbid wrong by destroying forbidden objects, particularly liquor and musical instruments are haram. 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 Afghanistan, Iran, Saudi Arabia, Nigeria, Malaysia, the Gaza Strip, etc., at various times and with various levels of power, to combat sinful activities and compel virtuous ones. (The power of the Saudi religious police was sharply curtailed in 2016)

Ma'ruf, usually translated as "good", "right" or "just", appears 38 times in slightly varying forms in the Qurʾān. Traditional commentators oppose the association of maʿrūf with its cognate urf, "custom."

Although most common translations of maʿrūf is "good" and munkar "evil", the words used for good and evil in Islamic philosophy are ḥusn and qubh. In its most common usage, maʿrūf is "in accordance with the custom", while munkar (singular nukr), which has no place in the custom, is the opposite. In today's religious expression, maʿrūf is best translated as sunnah and munkar as bid’a. (a related topic: Istihsan)

Depending on the translation from the Quran, the phrase may also be translated as commanding what is just and forbidding what is evil, commanding right and forbidding wrong, and other combinations of "enjoin" or "command", "right" or "just", "wrong", "unjust", or "evil".

Answering the question of why there is a duty among Muslims to forbid wrong are statements in the Quran and hadith.

Scholars have provided a number of reasons why the obvious reading of this verse is incorrect, such as that it refers not to the present but "to some future time when forbidding wrong will cease to be effective."