Amos asks this rhetorical question to expose Israel’s moral and spiritual corruption. The intent is to challenge their complacency and self-satisfaction by illustrating that their injustice is as unnatural as plowing rocky ground (Amos 6:12). It serves to awaken them to the consequences of turning justice into poison (Amos 6:12).

God, through Amos, condemns Israel’s injustice, highlighting that just as horses cannot run on rocks nor oxen plow barren land, Israel has corrupted justice into poison and righteousness into wormwood (Amos 6:12-13). This underscores the futility and unnaturalness of their moral decay.

Amos’s twin questions expose the self-evident impossibility of Israel’s moral inversions by grounding them in agricultural common sense. The Hebrew בַּסֶּלַע (bassela’, on the rock) indicates something obviously true, no farmer runs horses over rocky ground or tries to plow it with oxen. Both actions are futile to the point of absurdity. Having secured his audience’s assent to these obvious truths, Amos delivers the indictment: you have done something equally absurd and destructive, turned mishpat (justice) into rosh (poison/gall) and the fruit of righteousness into la’anah (wormwood, a bitter plant). The parallelism is exact: as rocks make farming impossible, so corrupted justice makes covenantal community impossible. The questions serve the prophet’s rhetorical purpose precisely because they require no argument; they win assent before anyone realizes the trap has closed. Israel cannot deny the agricultural truth without denying their own experience, and in conceding it they have conceded the moral charge.