The product that results when wine undergoes a fermentation by which the alcohol in the wine changes into acetic acid. The product was thought to be injurious to the teeth. The LXX here reads, “As a sour grape is hurtful to the teeth.”
As smoke.
In Solomon’s day, men were well acquainted with the sting of wood smoke in the eyes, for stoves and chimneys as we have them seem to have been unknown. Similarly annoying is the slothful messenger who is dilatory in carrying out his errand. The LXX renders the last clause, “so iniquity hurts those that practice it.”