The characters combine to paint a clear, literal, and almost cinematic sequence: one moves and lifts up (搬起) a rock (石头) in order to smash (砸) one's own (自己的) foot (脚).
This idiom has a long history in Chinese folklore and literature, but its modern significance is heavily tied to political rhetoric. It is famously a favorite phrase of the Chinese Ministry of Foreign Affairs. When criticizing policies or actions of other nations (particularly the United States) that they deem hostile or counterproductive, spokespeople will often state that these actions will inevitably “lift a rock only to drop it on their own foot.” This usage frames the other party's actions not just as wrong, but as foolish and ultimately self-defeating. Compared to the Western idiom “to shoot oneself in the foot,” 搬起石头砸自己的脚 carries a stronger implication of ill intent. While you can “shoot yourself in the foot” through a simple, careless mistake, “dropping a rock on your own foot” almost always implies you picked up that rock to throw at someone else first. It highlights a sense of cosmic justice or poetic irony, where a malicious act boomerangs back on the perpetrator. This reflects a common theme in Chinese thought that actions have natural consequences.
While famous for its political use, this idiom is versatile and appears in various modern contexts.