How should one who repented from usury deal with the profits generated from it? Is it permissible for him to gift it to a relative, and is it lawful for the recipient to take this money despite knowing its source?

If the profits are usurious interest resulting from lending with usury, then they must be disposed of by spending them on good deeds and acts of charity. However, if they result from investing these interests or bank loan funds, the preponderant opinion is that they are not permissible, because in this case the money does not follow the person's effort. It becomes permissible for its possessor if they are among those to whom such money is dispensed, like a poor person or a needy person.