The Ruling on Praying Behind a Usurer Before His Repentance and After It

The questioner says: We prayed for a long period behind a man who engaged in usury, and afterwards he repented to Allah the Exalted, but he did not return the money he had earned in excess to his partners. What is your guidance regarding our previous prayers and our current situation? May Allah reward you with good.
The prayer is valid, and praise be to Allah. Repentance is valid for whoever repents; Allah accepts the repentance of the one who repents with sincere repentance. If he was ignorant when he engaged in usury, then what has passed is forgiven for him. However, if he knew and was negligent, he must give in charity what he received from the usury, giving it to the poor and the needy. This is because Allah, Mighty and Majestic, says: [Surat al-Baqarah: 275]. If he repented to Allah when the admonition came to him and he learned of the prohibition, then what has passed is forgiven for him, and he does not have to return his previous transactions. But if he knew but was negligent and continued, then what he received from the usury is not permissible for him. Rather, it is obligatory for him to spend it in the causes of righteousness and good, such as charity for the poor and the needy, and charitable projects. He must not keep it for himself. Yes.
The presenter: May Allah reward you with good and do you good.