Proverbs 26:2 - Joseph Benson’s Commentary on the Old and New Testaments

As the bird by wandering Namely, from place to place: that is, as by its restlessness it secures itself from the fowler, that he cannot shoot at it, or spread his net over it; so the curse causeless shall not come Namely, upon the innocent person, but he shall escape from it as the bird escapes the fowler. Or, as some interpret it, “Curses which fly out of men's mouths causelessly, shall no more alight where they would have them, than a sparrow that wanders uncertainly, or a dove that flies away swiftly, will settle according to their direction.”