It would appear, from chap. iv. 9, that two sets of stones were set up, Joshua, following the spirit of the Divine direction, having caused a second set to be erected in the middle of the river on the spot where the priests had stood. Some have supposed that that verse is an interpolation of later date; but, as it occurs in all the manuscripts, and as it is expressly stated in the Septuagint and Vulgate versions that this was a different transaction from the other, we must accept it as such. The one memorial stood on the spot where the ark had indicated the presence of God, the other where the first encampment of the host had shown God's faithfulness to His word. Both seemed to proclaim the great truth afterwards brought out in the exquisite words of the psalm--"God is our refuge and our strength; a very present help in time of trouble." They might not be needed so much for the generation that experienced the deliverance; but in future generations they would excite the curiosity of the children, and thus afford an opportunity to the parents to rehearse the transactions of that day, and thrill their hearts with the sense of God's mercy. Among devout Israelites, that day was never forgotten. The crossing of the Jordan was coupled with the crossing of the sea, as the two crowning tokens of God's mercy in the history of Israel, and the most remarkable exhibitions of that Divine power which had been so often shown among them. In that wailing song, the seventy-fourth psalm, where God's wonderful works of old are contrasted in a very sad spirit with the unmitigated desolations that met the writer's eye, almost in the same breath in which he extols the miracle of the sea, "Thou didst divide the sea by Thy strength," he gives thanks for the miracle of the river, "Thou didst cleave the fountain and the flood: Thou driedst up mighty rivers." And in a song, not of wailing, but of triumph, the hundred and fourteenth psalm, we have the same combination:-- "When Israel went forth out of Egypt, The house of Jacob from a people of strange language; Judah became His sanctuary, Israel His dominion. The sea saw it, and fled; Jordan was driven back. The mountains skipped like rams, The little hills like lambs. What aileth thee, O thou sea, that thou fleest? Thou Jordan, that thou turnest back? Ye mountains, that ye skip like rams; Ye little hills like lambs? Tremble, thou earth, at the presence of the Lord, At the presence of the God of Jacob; Which turned the rock into a pool of water, The flint into a fountain of waters."