Narrated by Sayyiduna Abdullah bin Mas’ud (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: When a servant earns unlawful wealth and spends from it, it is not accepted from him, and if he gives charity from such wealth, that too is not accepted, and when he leaves behind such wealth, it becomes his provision towards Hell. The reason is that Allah Almighty does not erase evil with evil, rather He removes evil with good. Surely, one impure thing cannot erase another impure thing.