Passing a water pipe with ash in it for someone else to hit because they couldn't bong it. Either passing it to say fuck you to the next person, or just being a dumbass and not realize your handing an empty pipe.
Noob: *Cough, cough* Here, cash it man.
Stoner: Dip shit don't pass me an empty pipe. Now I have to ash it to pack a fresh bong.