Today we read about Achan, who took the accursed, or devoted, things (Jos 7:1). Everything that was in the city of Jericho was devoted for destruction, except the metal treasure, which belonged to the LORD and which was to go into the treasury of the LORD for the Tabernacle.
The word translated devoted can have a positive meaning or a negative meaning (as can all Hebrew words).
Nevertheless no devoted offering that a man may devote to the LORD of all that he has, both man and beast, or the field of his possession, shall be sold or redeemed; every devoted offering is most holy to the LORD. Lev 27:28
This is its positive meaning: an offering (or anything) which a man dedicates to the LORD, is from that day devoted or holy (set apart) to the LORD. That thing belongs to the LORD God now and shall be treated as such.
So none of the accursed things shall remain in your hand, that the LORD may turn from the fierceness of His anger and show you mercy, have compassion on you and multiply you, just as He swore to your fathers, Deu 13:17
This is its negative meaning. Idols or possessions of a town which has turned from the LORD and served idols, shall be gathered in the center of the city and burned entire, because those things have become devoted to the LORD for destruction. It is likewise set apart to the LORD just like the offering is, however since it is an accursed thing, it is set apart to the LORD for destruction. It also cannot be possessed by man because it is devoted.
The things that were in Jericho were devoted to the LORD for destruction – the negative meaning. Except for the metal treasure, that was devoted to the LORD for the treasury – the positive meaning. Either way, they were the LORD’s and did not belong to men.
So the man took for himself, that which had been devoted to the LORD: the garment, devoted to destruction, and the silver and gold, devoted or set apart for the treasury of the LORD. He trespassed against the LORD’s holiness.
Why was this such a big deal? The livestock and spoil of Ai was fine for Israel to keep for themselves – why not the things of Jericho?
Jericho was the first city of the Canaanites which Israel encountered. It was like a firstfruits offering to the Lord. Moses had commanded that when they harvested their fields, they were not just supposed to eat everything they harvested, but they were to take the first of the fruit which the harvest produced, and give it to the priests for the Lord. The firstfruits was set apart or holy to the LORD; i.e., it belonged to the LORD and not to the man who owned that field.
Well, Jericho was the first of all the cities of Canaan. It was devoted to the LORD for complete and utter destruction (its negative meaning), just as a firstfruits offering is devoted to the Lord for the priests (its positive meaning). That is why keeping the spoil of Jericho would bring a curse. It is a more serious offense than just coveting a few things.
Remember that Ananias and Saphira in Acts were struck dead for lying to Peter about the thing that they had devoted to the LORD? The church at Jerusalem was the first of the churches throughout the whole earth. It was the LORD’s firstfruits. God was and is very zealous for the holiness and purity of His first things.
At Ai, now that the firstfruits of Canaan — Jericho — had been given to the LORD, the men had permission to take the spoil of Ai for themselves. There was nothing wrong with Israel having things. Achan’s sin was desiring to keep the LORD’s devoted things.
For further study: Compare the two encounters of Israel with Ai. (Comparison is a teaching tool of Scripture!) In the first encounter, Israel was defeated, and in the second encounter, they were victorious. What happened before the second encounter that did not happen before the first encounter? Israel was victorious at Jericho – can you see the pattern?