He whetted it up and down all day long.

Every odd moment he could find he had the knife and stone out and was whetting away.

The steel acquired a razor edge.

He tried it with the ball of his thumb or across the nail.

He shaved hairs from the back of his hand, glanced along the edge with microscopic acuteness, and found, or feigned that he found, always, a slight inequality in its edge somewhere.