When Muhammad Ali was filming the historical TV drama "Freedom Road" in the late 1970's, he painted a boxing scene and included in it, one of his famous poems.

The poem goes, “Ref, he did float like a butterfly and sting like a bee."

The ref running away says, “And if you were smart you would run like me."

The painting is just one of the works by the heavyweight champion boxer and activist, who died in 2016, that are part of an auction Tuesday at Bonhams Auction House in Midtown.

The Ali artwork is all from the collection of Rodney Hilton Brown, a longtime friend of the man known as "The Greatest." Brown had taken over a failing Soho art gallery in the late 1970s and met up with Ali after a charity fight in Boston, hoping he would paint some limited editions for him.

"I told him if I could get a paint brush in these hands I think something is going to come out on a different canvas," said Brown, who says at that point Ali smiled because he was already painting.

He had learned from his father Cassius Clay Sr. Brown and Ali later met up, and as Brown says, the rest is history.  

The artwork covers many themes, from boxing, to social justice. There are also paintings from Clay Sr., including one of Ali's Mother Odessa. Bonhams director of popular culture Helen Hall says when she first saw Brown's collection, she got goosebumps.

"I think the works are so incredible, they are so emotional because they are topics that were so close to Ali's heart, so yeah, I was really blown away," said Hall.

Describing his relationship with one of the 20th century's most significant figures, Brown says, they had fun. He points out two paper airplanes being auctioned off that Ali had made and thrown at him. He says he is ready to part with his collection, which he says has been sitting underneath his dining room table boxed up for more than 40 years.

"Believe it or not, I'm 78 years old, and I don't have a big pyramid so it's got to go, everything's got to go," said Brown, who added “Everything has to get shared with the world now.”

Find out more about the auction at bonhams.com/auctions.