On Thursday, Ali was hospitalized for a respiratory issue as a precaution and by Friday, his issues were serious enough to draw family members to his bedside.
Here are some of The Champ's most widely-recognized quotes:
1. “He who is not courageous enough to take risks will accomplish nothing in life.”
Muhammad Ali, 'The Greatest' Boxing Legend, Dies at 74
2. “A man who views the world the same at 50 as he did at 20 has wasted 30 years of his life.”
3. “Float like a butterfly, sting like a bee, your hands can’t hit, what your eyes can’t see.”
4. "I am the greatest. I said that even before I knew I was. I figured that if I said it enough, I would convince the world that I really was the greatest."
5. “Only a man who knows what it is like to be defeated can reach down to the bottom of his soul and come up with the extra ounce of power it takes to win when the match is even.”
Muhammad Ali the Grammy-Nominated, Billboard-Charting Musician
6. “I hated every minute of training, but I said, ‘Don’t quit. Suffer now and live the rest of your life as a champion.'”
7. “It’s just a job. Grass grows, birds fly, waves pound the sand. I beat people up.”
8. “The man who has no imagination has no wings.”
9. “People don’t realize what they had till it’s gone. Like President Kennedy, there was no one like him, the Beatles, and my man Elvis Presley. I was the Elvis of boxing.”
This article originally appeared on THR.com.