In a speech in California today, Clinton reflected on watching Ali light the Olympic torch in Atlanta while his hands shook from Parkinson's Disease.
"Once the most graceful, powerful athlete in the world, with his hands shaking, holding on, he did his job," Clinton said. "And in the very end he was actually astonishingly good humored about the burden of his later years. So by the time he died, who he was as a person was greater than his legend."
Ali's body will return to Louisville in the next 24 to 48 hours with his family and a private service will be held for immediate family Thursday, family spokesman Bob Gunnell said at a news conference in Phoenix today.
On Friday, the family will be joined by an imam at the funeral home for prayers, Gunnel said.
A procession Friday will lead through the streets of Louisville, traveling down the street named after him and passing through Ali's old neighborhood. The procession will end at Cave Hill cemetery, where he will be laid to rest.
The service will be led by an imam and will include clerics from multiple religions.
"This entire service was his specific request," Gunnell said. "He truly loved all people."
The service will be streamed throughout the world, Gunnell said.
After the memorial service, a private reception for friends and guests is scheduled at the Muhammad Ali Center in Louisville.
Gunnell said Ali became ill Monday and was hospitalized Monday night in Arizona in fair condition.
"The family was called when things became more serious," but they "still had a lot of hope that it was going to turn around," Gunnell said.
Ali "has battled back man times. And we expected it to happen this time," Gunnell said.
All family members were brought in in the last 24 hours, and they were given time to say goodbye, he said.
"His final hours were spent with just immediate family," Gunnell said.
Ali died Friday at 9:10 pm MT, and the cause of death was "septic shock due to unspecified natural causes," he said.
Ali's brother Rahaman Ali told ABC News today in their last conversation, "He said to me with shaking, he said, 'Rahaman how do I look?' I said, 'You look the same to me, you look the same with all that shaking.' He said to me, 'I’m in no pain. No pain.' He said, 'Don't cry for me, Rahaman. I’m going to be with Allah god. I made peace with God. I'm OK.'"
Ali's daughter Hana Ali said in an emotional post on Twitter today, "All of us were around him hugging and kissing him and holding his hands, chanting the Islamic prayer. All of his organs failed but his HEART wouldn't stop beating. For 30 minutes... his heart just keep beating. No one had ever seen anything like it. A true testament to the strength of his Spirit and Will!"