Revision Quotes
Although this quotation has been cited by many scholars, none has yet given a primary citation. As a result a few researchers question the attribution to Keynes and argue that the first primary source of this notion was the Nobel Laureate in Economics Paul Samuelson -- Quote {645739}. However, even Samuelson attributed this quotation to Keynes although he did not do so at this particualr interview.
According to Quote Investigator, Oscar Wilde said, to his hostess at a country house who asked him how he'd spent the day, some variation of: "In the morning, after hard work, I took a comma out of one sentence...In the afternoon, I put it back in again." See http://quoteinvestigator.com/2015/10/25/comma/
He was too ill to read the speech himself and it was read by James Wilson for him.