Final answer:
The metaphor of the spinning wheel in the poem symbolizes the relentless and continuous passage of time.
Step-by-step explanation:
The metaphor in the lines from the poem "Turn, turn, my wheel! Turn round and round, Without a pause, without a sound: So spins the flying world away!" is being used to illustrate the passage of time. The wheel's continuous spinning without pause or sound symbolizes the relentless and quiet progression of time in the world, which keeps moving forward irrespective of individual events or feelings.
In the lines, 'Turn, turn, my wheel! Turn round and round, Without a pause, without a sound: So spins the flying world away!' the metaphor is being used to illustrate the passage of time. The speaker compares the spinning wheel to the spinning of the world, signifying the continuous and unceasing movement of time.