How to Sharpen a Knife

Your metaphor is your whetstone; choose well.
Perhaps a swallow, a comet, a bell,

an amethyst, the moon. Wet it with tears,
a typhoon, the amber sap wrung from fears.

Lay one side of the blade, dull edge against stone,
and hone it thus, hard, as though against bone.

In one direction only; back and forth,
and the metal splays rough, loses its worth.

Now the other side, slow easy strokes, same
direction, wide edge to the point of pain.

Tendered thus, when you thrust the sharpened
blade between unwary ribs, it should rend

as if through parchment, shearing burnished art
past muscle, sinew, deep into the heart.