“ And it shall be that, when the soles of the feet of the priests who bear the ark of YHWH, the Lord of all the earth, shall rest in the waters of Jordan, that the waters of Jordan shall be cut off, even the waters that come down from above. And they shall stand in one heap.”
As Joshua 3:8 told us they were to advance on the Jordan and stand still with their feet in the water. Now they were told why. It was because as they stood there the waters would be cut off and would cease coming down the river bed, and would stand in one heap. This may well have occurred because a downfall of sand and rock had blocked the river at exactly the right time, heaping the waters up. Such downfalls of sand and rock are known to have achieved this situation from time to time with the Jordan, and it has often been observed. One such occurred while Garstang was there. The main miracle here was the timing.
“The Ark of YHWH, the Lord of all the earth.” A slightly different phrase than in Joshua 3:11. There the covenant of YHWH with His people was pre-eminent, here it was YHWH as the God of battle Who was in mind, as Joshua 6:8 onwards demonstrate. Both are intertwined in the whole account. Notice again ‘the Lord of all the earth'. No one else could stop the waters of the Jordan. They were going across in covenant with YHWH, and they were going across to do battle, and the Lord of all the earth was with them.