Causeless Curses Cannot Land: The Sparrow's Flight
As Joseph Exell clarifies in *The Biblical Illustrator* (1887), the proverb means: "Unsteady as the sparrow, as the flight of the swallow, is a causeless curse; it cometh not to pass." Exell identifies two categories of causeless imprecations.
Proverbs 26:2UniversalGod's protection of the righteouspowerlessness of unjust words