2 As the bird by wandering, as the swallow by flying, so the curse causeless shall not come.
1. The folly of passion. It makes men scatter causeless curses, wishing ill to others upon presumption that they are bad and have done ill, when either they mistake the person or misunderstand the fact, or they call evil good and good evil. Give honour to a fool, and he thunders out his anathemas against all that he is disgusted with, right or wrong. Great men, when wicked, think they have a privilege to keep those about them in awe, by cursing them, and swearing at them, which yet is an expression of the most impotent malice and shows their weakness as much as their wickedness.
2. The safety of innocency. He that is cursed without cause, whether by furious imprecations or solemn anathemas, the curse shall do him no more harm than the bird that flies over his head, than Goliath’s curses did to David, 1 Sam. 17:43. It will fly away like the sparrow or the wild dove, which go nobody knows where, till they return to their proper place, as the curse will at length return upon the head of him that uttered it.
– Matthew Henry Commentary