“Rule of Thumb” by W.S. Merwin

When my thumb touches my little finger
a door opens that I forgot was there
a door of air forgotten in the air

the thumb knows that door through which I came
but what the thumb knows is before knowledge

it does not listen with its map of hearing
it hears the harmony the fingers play

I cannot go back through that door again
and the thumb will not guide me anywhere
pointing the way home for the thumb is there