Author Henry James famously remarked that "the two most beautiful words in the English language" are what?

Henry James (15 April 1843 – 28 February 1916) was an American author, who became a British subject in the last year of his life, regarded as a key transitional figure between literary realism and literary modernism and is considered by many to be among the greatest novelists in the English language. He was the son of Henry James Sr. and the brother of renowned philosopher and psychologist William James and diarist Alice James.

One of Henry James's quotes is: “Summer afternoon - summer afternoon; to me those have always been the two most beautiful words in the English language.”