יהושע, פרק ז׳, פסוק ט״ז

On the morning following the defeat at the city of Ai, a tense investigation begins to uncover the individual who secretly took from the forbidden spoils. The entire nation and its tribes are brought forward to participate in a lottery [ביאור שטיינזלץ]. This critical process unfolds before the High Priest, specifically relying on his breastplate, which bears the engraved names of all the tribes.

The identification of the guilty tribe does not happen through ordinary means, but rather through a miracle. God provided Joshua with a clear sign beforehand: the gemstone on the breastplate belonging to the tribe of the sinner would lose its natural glow and become dark. As the tribes stand before the High Priest, the stone representing the tribe of Judah suddenly dims. This visible change clearly reveals that the guilt lies within their ranks [רש״י].