The Pirke De-Rabbi Eliezer taught that when Israel sinned in the matter of the devoted things, as reported in Joshua looked at the 12 stones corresponding to the 12 tribes that were upon the High Priest's breastplate. For every tribe that had sinned, the light of its stone became dim, and Joshua saw that the light of the stone for the tribe of Judah had become dim. So Joshua knew that the tribe of Judah had transgressed in the matter of the devoted things. Similarly, the Pirke De-Rabbi Eliezer taught that Saul saw the Philistines turning against Israel, and he knew that Israel had sinned in the matter of the ban. Saul looked at the 12 stones, and for each tribe that had followed the law, its stone (on the High Priest's breastplate) shined with its light, and for each tribe that had transgressed, the light of its stone was dim. So Saul knew that the tribe of Benjamin had trespassed in the matter of the ban.