Why is money earned from usurious interest – which has been described as illicit – spent on the poor and needy?

Usurious gains are ill-gotten wealth for whoever possesses them unlawfully, but they are permissible for the poor and the needy if acquired through a legitimate channel. For wealth belongs to Allah; He permits it to whomever He wills and forbids it to whomever He wills. This is supported by the hadith of Barirah, where charity was forbidden for the Messenger of Allah, peace be upon him, but the change in the cause of ownership rendered it no longer charity in his regard. Thus, the Usuliyyun (jurists specializing in the principles of Islamic jurisprudence) say: "A change in the cause of ownership is like a change in the essence of the thing itself." Imam al-Nawawi mentioned in Al-Majmu' that if unlawful wealth is given to a poor person, it does not become unlawful for them; rather, it is lawful and good for them.