יהושע, פרק ז׳, פסוק י״ג

The presence of forbidden property within the Israelite camp acts like a hidden poison, slowly seeping into the nation and causing profound harm [ביאור שטיינזלץ]. To cure this, the people are commanded to get ready for a public process of rooting out the evil from their midst. The primary approach among commentators is that the call to sanctify themselves is actually a command to prepare and gather. They must ready themselves to pass before the Ark of the Covenant, where the individual responsible for bringing disaster upon them will be revealed [מצודת דוד].

There are different traditions regarding how this dramatic identification takes place. One approach suggests a physical reaction as the nation passes before the Ark: the guilty person is physically halted by the Ark's presence, completely unable to move from his spot. Another tradition involves the Urim and Thummim. In this scenario, the tribes stand before the high priest's breastplate, and the specific gemstone representing the guilty tribe loses its bright glow and turns dark. Once the guilty tribe is identified, a lottery system using drawn ballots is used to narrow down the exact family and, ultimately, the individual sinner [רד״ק].

God warns the people that they will remain powerless against their enemies until the forbidden property is entirely removed. Interestingly, God only states the need to remove the banned items, intentionally leaving out any mention of the severe punishment of death and destruction that awaits the sinner. This omission is a deliberate tactic. If the guilty individual knows in advance that a death sentence is inevitable, he might completely refuse to confess to his crimes [מלבי״ם].