Zulm (Oppression/Injustice) is one of the most condemned acts in Islam. The word literally means "to put something in its wrong place." Allah says in a Hadith Qudsi, "O My servants, I have forbidden Zulm for Myself and I have made it forbidden among you, so do not oppress one another." There are three types of Zulm: injustice against Allah (Shirk), injustice against oneself (sinning), and injustice against others (violating their rights).
The Quran declares: "Indeed, Allah does not do injustice (zulm), even an atom's weight" (4:40). Allah's perfection includes absolute justice; injustice is a human failing. The Hadith Qudsi emphasizes: "O My servants, I have forbidden oppression (zulm) for Myself, and I have made it forbidden among you, so do not oppress one another" (Muslim). This establishes that injustice is not only prohibited but is against the very nature of Allah's creation.
The consequences of zulm are severe. The Prophet said: "Beware of injustice, for injustice will be darkness on the Day of Resurrection" (Bukhari, Muslim). This darkness will be overwhelming for the oppressor, while the oppressed will have light. The supplication of the oppressed is especially powerful. The Prophet said: "Beware the supplication of the oppressed, for there is no barrier between it and Allah" (Bukhari, Muslim). This means that Allah responds directly to the prayer of the oppressed, even if the oppressor is unaware.
The Quran commands believers to stand for justice even against themselves or their families: "O you who have believed, be persistently standing firm in justice, witnesses for Allah, even if it be against yourselves or parents and relatives" (4:135). In Islamic history, rulers were warned that their injustice would bring downfall. The saying "Justice is the foundation of governance" ('adl asas al-mulk) reflects the belief that societies built on justice thrive, while those built on oppression collapse. Confronting injustice is a form of helping both the oppressor and the oppressed.