‘And it happened that, when he was come, he blew a ram's horn in the hill country of Ephraim, and the children of Israel went down with him from the hill country, and he in front of them. And he said to them, “Follow me. For Yahweh has delivered your enemies the Moabites into your hand”.'
On arrival in the hill country of Ephraim Ehud blew a trumpet of ram's horn (Joshua 6:13), and the waiting army came to him and he led them back towards where he had come from, telling them that all was well. The plan had worked successfully, and the Moabites were there for the taking.
When Israel had cried to Yahweh (verse 15) that included the fact that the covenant had again become an important factor in their thinking. But not all had deserted the covenant. There were still those who met at the central sanctuary and were faithful to it. It was probably to them that Ehud had gone for help, sending out the covenant call. And this was their response to aid one of their number in need. But the plan had probably been his.
‘And they went down after him, and took the fords of Jordan against the Moabites. And would not allow any man to pass over.'
From this it is clear that an army of occupation was settled in the region round the city of palms, possibly there to receive tribute and to remind Israel of their strength. They did not realise that Reuben/Gad/Benjamin had renewed their covenant with the tribal confederation and had thus become much stronger, gaining support from the other tribes.
And this army now found itself leaderless and trapped, for the death of the king would throw everything into confusion. For in those days when a king died there would be a number of contenders for the throne, and the internal battles would begin. Thus when they made for the fords to enter into the leadership contest they found the fords closed against them, although undoubtedly messengers had previously been despatched and passed over to declare the death of the king. Nor could assistance come from beyond Jordan because of the presence of these Israelite soldiers.