the blade and the hand, whichever one i am

In the dream I'm standing in a kitchen I don't recognise, and the chef hands me a knife without saying a word. But instead of making it sharp, I run my thumb along the edge and it leaves a thin line of light on the steel, like dawn on a wet window. For a long time I've thought I was the hand doing the work, but this morning I woke up not knowing if I'm the blade or the stone that gets worn down instead. Neither one of them gets to speak, and maybe that's the part I keep coming back to.