A comma, England, Wilde, which idiom is this writing?

Saturday, May 2007, 12, 6:38 p.m.

Once, Oscar Wilde, a famous British writer, gave a banquet. The guests got together and waited for a long time in the living room, but they didn't see the arrival of the host. They are very anxious. Later, Wilde hurriedly apologized to the guests. When the guest asked him what he had done, he replied, "I am revising my poem." The guest asked again, "You must have done a lot of work for so long?" Wilde said with a smile, "I have done an extremely important job. I deleted a comma and later found it inappropriate and added another one. "

Idiom: Repeated scrutiny