Jamieson, Fausset and Brown on Joshua 4:4-5

4-5. Joshua called the twelve men--They had probably, from a feeling of reverence, kept back, and were standing on the eastern bank. They were now ordered to advance. Picking up each a stone, probably as large as he could carry, from around the spot "where the priests stood," they pass over before the ark and deposit the stones in the place of next encampment (Jos 4:19, 20), namely, Gilgal.