Joshua 4:19
And the people came up out of Jordan on the tenth day of the first month, and encamped in Gilgal, in the east border of Jericho. And the people came up out of Jordan on the tenth day of the first month, and encamped in Gilgal, in the east border of Jericho.
The tenth day of the first month marks the completion of the miraculous crossing, when after the priests bearing the ark stepped up onto dry land the Jordan resumed its flow and returned to its course. The first encampment west of the river was made at Gilgal, on the eastern edge of Jericho. The stones lifted from the riverbed were erected there as a monument to keep the crossing in remembrance. The dividing of the waters proved the Jordan subject to the same divine power displayed at the Red Sea, and the sight strengthened the faith of the people. That stone memorial was to preserve the account of deliverance for succeeding generations and to testify to mighty power, that all might learn to fear Him.