Albert Barnes Commentary Proverbs 10:26

"As vinegar to the teeth, and as smoke to the eyes, So is the sluggard to them that send him." — Proverbs 10:26 (ASV)

The teeth set on edge by the sour wine used by peasants (Ruth 2:14; Psalms 69:21), the eye irritated by wood-smoke, these shadow the annoyance of having a messenger who will loiter on the way.