18. and ye, in any wise keep yourselves from the accursed thing--Generally they were at liberty to take the spoil of other cities that were captured (De 2:35; 3:7; Jos 8:27). But this, as the first fruits of Canaan, was made an exception; nothing was to be spared but Rahab and those in her house [Jos 6:17]. A violation of these stringent orders would not only render the guilty persons obnoxious to the curse, but entail distress and adversity upon all Israel, by provoking the divine displeasure. These were the instructions given, or repeated (De 13:17; 7:26), previous to the last act of the siege.

JFB.