(1) explained the season (autumn) and place of farewell, rendered the bleak and desolate atmosphere when parting, set off the poet's desolation, and laid the groundwork for later writing.
(2) The first sentence renders the sadness of parting with scenery, and the bleak west wind renders the desolation of parting; The second sentence directly expresses the sadness of parting, and the sadness of saying goodbye to Fujian is heartbreaking. The two sat silently without touching a drop of wine; The third sentence exhorts friends to remember the place of departure at this time, suggesting that friends are about to leave, and loneliness and sadness begin; The sentence at the end is lonely and hazy, always watching lonely friends drift away, condensing and deepening the sadness of parting.