Beware: your enemy is shrewd

they on their part acted with cunning...
Joshua 9:4a

The children of Israel were conquering the promised land city by city. They had just obliterated Ai. Then they had a massive meeting where all of Israel renewed their covenant with God.

The next thing that happens of note is that this rag dressed group of guys comes along, saying they are from a far off country and plead for Joshua to make a special covenant with them of peace. they hung out for three days and then the covenant was made.

When Joshua figured out that he had been deceived, he cursed them, but the covenant still stood.

What's the point of the story? If the enemy can't get you head on, he goes to the side where you don't expect it with deception. He tries to get you to agree to something through lies. Seems like a contract would be no good that you signed if it was "sold" to you on lies, but that's not true. Once you've entered in to the contract, it's hard or impossible to get out of it. So be careful before you "sign on the dotted line" or make that promise.

Joshua and the leaders had just had a huge victory, followed by a solemn and glorious re-dedication to God. They were getting ready to go after the next cities and then the above event occurred. Watch out for deception. The enemy is shrewed, cunning, and crafty.