Answer:
What is often returned but is never borrowed?
My first keeps time, my second spends time, my whole tells time.
A house of wood in a hidden place. Built without nails or glue. High above the earthen ground. It holds pale gems of blue.
I can be written, I can be spoken, I can be exposed, I can be broken.
A precious stone, as clear as diamond. Seek it out while the sun's near the horizon. Though you can walk on water with its power, try to keep it, and it'll vanish in an hour.
What is always coming but never arrives?