John Calvin Commentary Joshua 3:15

"and when they that bare the ark were come unto the Jordan, and the feet of the priests that bare the ark were dipped in the brink of the water (for the Jordan overfloweth all its banks all the time of harvest,)" — Joshua 3:15 (ASV)

And as they that bare the ark, etc. The valor of the priests in proceeding boldly beyond the riverbed into the water itself was deserving of considerable praise, since they could have been afraid of being instantly drowned. For what could they expect on placing their feet in the water, but immediately to find a deep pool in which they would be engulfed? In not being afraid on reaching the stream, and in continuing to move firmly forward to the appointed place, they gave an example of rare promptness, founded on confidence.

To the general danger was added the special one that the Jordan had then overflowed its banks, as it usually does at the beginning of every summer. As the plain was covered, it was impossible to observe the line of the banks or the ford, and the mud, spread far and wide, increased their fear and anxiety.

God was pleased that His people, and especially the priests, should contend with these obstacles, so that the victory of their faith and steadfastness might be more renowned. At the same time, the difficulty thus presented tended to magnify the glory of the miracle when the waters, which had overflowed their banks, retreated at the divine command and were gathered together into a solid heap.

First, Joshua explains the nature of the miracle for the purpose of removing doubt and preventing ungodly men from denying the divine intervention by a subtle searching for other causes. It is not, indeed, impossible that the flowing of the water might have been restrained for a short time, and that some portion of the channel might thus have appeared dry, or that the course might have changed and taken some other direction. But it was certainly neither a natural nor an accidental event when the waters stood gathered up into a heap. It is therefore said that the waters which previously flowed from the higher ground, seeking in their descent a continuous outlet, stood still.

There cannot be a doubt that this wonderful sight must have been received with feelings of fear, leading the Israelites more distinctly to acknowledge that they were saved in the midst of death. For what was that collected heap but a grave in which the whole multitude would have been buried, had the waters returned to their natural liquid state?

Had they walked upon the waters, their faith might have served them as a kind of bridge. But now, while mountains of water hung over their heads, it is just as if they had found an open and level path beneath them.

The locality is marked out as situated between two cities, so that its memory might never be lost; and, likewise, God ordered stones to be set up as a perpetual memorial, so that this distinguished mercy might be celebrated by future generations in all ages.