Proverbs 10:26 - Clarke's commentary and critical notes on the Bible

As vinegar to the teeth, and as smoke to the eyes, so is the sluggard to them that send him. As vinegar to the teeth - The acid softening and dissolving the alkali of the bone, so as to impair their texture, and render them incapable of masticating; and as smoke affects the eyes, irritating their tender vessels, so as to give pain and prevent distinct vision; so the sluggard, the lounging, thriftless messenger, who never returns in time with the desired answer.