“Come near, put your feet on the necks of these kings.” This seems harsh, but war is harsh and definite: someone is going to die, and if Israel’s warriors were not determined enough, it would be them. This was not something that Joshua did regularly, so there had to be a reason to encourage the men and give them a clear idea of what God was doing in their midst as they were determined enough to get the job done. Sadly, Israel was not always determined to get the job done, and as we see in Judges 1, the Israelites did not always have the determination to obey God when it came to the hard work of taking possession of the land (Judg. 1:21, 27-35). That disobedience cost them dearly both in not having a completely Israelite country and in later wars that had to be fought, for example in the time of David.
“They came near and put their feet.” The theme in Joshua that Joshua obeyed God is picked up here as the commanders obey Joshua.