Answer:
This thing all things devours: Birds, beasts, trees, flowers; Gnaws iron, bites steel; Grinds hard stones to meal; Slays king, ruins town, And beats high mountains down.
Runs smoother than any rhyme, loves to fall but cannot climb!
What can be filled with empty hands?
Forward Iām heavy, but backwards Iām not.
What measures out time until in time all is smashed to it?
I am your mother's brother's only brother in law. Who am I?