Boxing promoter Don King and Jesse Jackson also stepped out to pay tribute to the heavyweight champ.
Thousands turned out to pay tribute to Muhammad Ali during an Islamic funeral prayer service in his honor on Thursday.
Family, friends, fans and a number of religious officials remembered the heavyweight champ during Jenazah, the religious service following Muslim tradition, at the Kentucky Exposition Center in Louisville, Kentucky, after he died at the age of 74 on June 3.
The location was no coincidence, either: it commemorates Ali's final fight in Louisville on Nov. 29, 1961, when he defeated Willi Besmanoff.
Ali's second wife, Khalilah Camacho-Ali, and fourth wife, Lonnie Ali, were both in attendance, as was his daughter, Laila Ali, her husband, former NFL player Curtis Conway, and their two children, son Curtis Jr. and daughter Sydney.
The only three-time World Heavyweight Champion, who died after a decades-long battle with Parkinson's disease, was also remembered by boxing promoter Don King, Jesse Jackson, and Louis Farrakhan, head of the Nation of Islam.
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"To be properly prepared for burial, prayed over and then buried is a right owed to every single Muslim. If no one fulfills those rights, then the entire community has fallen into sin," Imam Shakir, a U.S. Muslim scholar who will also speak at Ali's funeral, told the crowd. "In the case of someone of Muhammad Ali's stature, to leave any of those rights unfulfilled would be a crime."
Meanwhile, another scholar, Sherman Jackson, spoke during the service to say, "He was a gift to his people, his religion, his country, and ultimately, to the world. Ali was an unapologetic fighter for the cause of black people in America. Ali was the people's champion, and champion he did the cause of his people."
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Ali's funeral will be held on Friday in his Louisville hometown at the KFC Yum! Center. The service, which will be open to the public and livestreamed online, will include speakers not only from the Muslim faith, but also Catholicism, Judaism, Buddhism and Mormonism.
Will Smith will serve as a pallbearer during the service, while Bill Clinton and Billy Crystal will be among those who give eulogies. You can hear the Clintons' touching memories of Muhammad Ali in the video below.