Joseph reveals his identity to his brothers 12:88-92
12:88 And when they presented themselves before him they said, 'O mighty prince, we and our people are afflicted with distress. We have brought but little merchandise. Fill up the measure, and be charitable to us; Allah rewards the charitable.'
12:90 They said, 'Are you Joseph?' 'I am Joseph,' he answered, 'and this is my brother. Allah has been gracious to us. Those who keep from evil and are patient, indeed, Allah does not let the wage of the good doers go to waste.'