The Feb. 1 letter asks Khamenei to release Josh Fattal and Shane Bauer, who were arrested while hiking in northern Iraq near the Iranian border. A third hiker, Sarah Shourd, was released on bail in September, shortly after Ali first wrote to Khamenei.

Ali’s letter asks Khamenei as a brother in Islam to show the same mercy and compassion for the two men.

Ali founded his center for world peace in Louisville, where he grew up and launched a boxing career that included three world heavyweight titles.