The line usually quoted as “The first draft of anything is garbage” is a softened, internet-era paraphrase. No book, letter, or interview ever printed those words from Hemingway.
The closest real source is Arnold Samuelson’s 1984 memoir With Hemingway: A Year in Key West and Cuba, which recalls Hemingway telling him in 1934: “The first draft of anything is shit.” Samuelson was a 22-year-old aspiring writer who spent about a year as Hemingway’s deckhand and pupil in Key West; his manuscript went unpublished until after his own death, so the exact wording rests on one man’s decades-old memory, not on anything Hemingway wrote himself.
No citation anywhere uses the word “garbage.”