One of the most surprising moments from this weekend's "SNL 40" special came when cast member Kenan Thompson briefly popped up to play Bill Cosby during a "Celebrity Jeopardy!" sketch. Unbeknownst to viewers, though, was who was originally supposed to portray the embattled comedian.

In a lengthy series of tweets posted on Wednesday, former "Saturday Night Live" star Norm Macdonald, who starred in numerous "Celebrity Jeopardy!" parodies during his "SNL" stint in the early '90s, revealed that the Cosby impression was initially supposed to be performed by Eddie Murphy. Murphy, who made his first return to Studio 8H after more than 30 years in honor of the show's anniversary, is well-known for his Cosby impression, and as Macdonald wrote on Twitter, he was offered the gag for Sunday's event.

"It's my job to talk him in to doing Jeopardy," Macdonald wrote of Murphy, detailing the planning and writing that went into the sketch in the days before "SNL 40" was set to air. "We talk in his dressing room a good hour. When it's over, I'm convinced he'll do it. He doesn't."

The reason, Macdonald said, was that Murphy didn't want to "kick a man when he is down," alluding to the multiple rape and abuse allegations that have swirled around Cosby in recent months. And while Macdonald declined to comment on what he thinks about Cosby's recent troubles, he said he respected Murphy's decision, saying it proved that Murphy was not a self-serving comedian.

Cosby later released a statement to NBC News thanking Murphy for declining to play him.

"I am very appreciative of Eddie and I applaud his actions," the statement said.

[via: Norm Macdonald, NBC News, h/t Esquire]

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