Curses are like chickens, they come home to roost.

Meaning: Malicious words and wishes eventually harm the person who spoke them, returning with consequences.

Origin: Chaucer's The Parson's Tale (c. 1390) already says that a wrongful curse returns to the one who made it, as a bird returns to its own nest. The chicken version was popularized by the poet Robert Southey, who used "Curses are like young chickens, they always come home to roost" as the motto of The Curse of Kehama (1810).