he said to the one he thought would be saved mention me to your master. however satan made him forget to mention him to his master and so joseph remained in prison for a number of years.
وقال للذي ظن أنه ناج منهما اذكرني عند ربك فأنساه الشيطان ذكر ربه فلبث في السجن بضع سنين