Is the money a Muslim receives from the German government—which relies on usury for its financing—lawful or unlawful?

If you took the money rightfully, without deceit or fraud, then it is permissible for you to benefit from it and save it, and it is not forbidden for you simply because it comes from a country that deals with usury. However, if there was deceit or fraud against the state, and you did not meet the required conditions for the grant, then this money is not permissible for you. It is better for one who is able to earn a living to spend from the work of his own hands, for the Prophet, peace and blessings be upon him, said: "No one has ever eaten food better than that which he eats from the work of his own hand."