I could a tale unfold whose lightest word Would harrow up...

I could a tale unfold whose lightest word Would harrow up thy soul, freeze thy young blood, Make thy two eyes like stars start from their spheres, Thy knotted and combined locks to part, And each particular hair to stand on end Like quills upon the fretful porpentine. But this eternal blazon must not be To ears of flesh and blood. List, list, O list!