Answer:
What measures out time. Until in time all is smashed to it?
What gets wet while drying?
I am nothing really at all, Yet I am easily found; Ignore me at your own peril, and you might end up crowned!
It holds no blessings in disguise. Its rhymes are aimed at your demise, it's cast only to ruin, Whatever you are doin'.
It holds most knowledge that has ever been said. But is not the brain, is not the head. To feathers and their masters, it's both bane and boon One empty, and one full.
It weighs next to nothing but no one can hold it for long. What is it?