Ongi (옹이) — where the tree closed over

Split enough firewood and you come to the place where the axe bounces back at you. That is 옹이, ongi.

An ongi forms where a branch was attached, or where one broke off. A tree cannot undo an injury. What it does instead is lay ring after ring around it and slowly close it in. Closed over, and closed over again — that is the knot.

So it is the hardest part of the wood. It takes the edge off a saw, catches a plane, throws an axe back. Carpenters cut around them. The grain is not handsome there, they say. It won't fetch a price.

And yet look at the posts in an old house and the knots are all still in them, dark and round, set into the wood like eyes. The longer a post has been standing, the more of them it has.

My father had a place like that on the back of his hand. Something he did when he was young, he said. The skin was thicker there, and it never chapped, not even in winter.