Two years after the death of Oscar Wilde one of his friends named Robert H. Sherard released a privately printed volume titled “Oscar Wilde: The Story of an Unhappy Friendship”. In 1905 the book was published publicly, and was soon followed by other biographical works about Wilde written by Sherard.
In ‘Unhappy Friendship’, Sherard recounted the comma story, and the context suggested that he’d heard the tale directly from Wilde.
While this story had appeared as early as 1884 in newspapers, under various titles including “Oscar’s Morning Work”, this retelling by Sherard became the most well known and became the basis for the many versions and adaptations of the quote that have been disseminated.
From Sherard’s telling the quote goes:
“I was working on the proof of one of my poems all the morning and took out a comma.”
“And in the afternoon?”
“In the afternoon—well, I put it back again.”
For a more extensive explanation of the citations and history of this story and quite, you should check out the QuoteInvestigator’s reporting of the history of this famous quote.