The Book of Joshua 4:8-14 (NIV)

8 So the Israelites did as Joshua commanded them. They took twelve stones from the middle of the Jordan, according to the number of the tribes of the Israelites, as the LORD had told Joshua; and they carried them over with them to their camp, where they put them down. 9 Joshua set up the twelve stones that had been ^[a] in the middle of the Jordan at the spot where the priests who carried the ark of the covenant had stood. And they are there to this day. 10 Now the priests who carried the ark remained standing in the middle of the Jordan until everything the LORD had commanded Joshua was done by the people, just as Moses had directed Joshua. The people hurried over, 11 and as soon as all of them had crossed, the ark of the LORD and the priests came to the other side while the people watched. 12 The men of Reuben, Gad and the half-tribe of Manasseh crossed over, armed, in front of the Israelites, as Moses had directed them. 13 About forty thousand armed for battle crossed over before the LORD to the plains of Jericho for war.14 That day the LORD exalted Joshua in the sight of all Israel; and they revered him all the days of his life, just as they had revered Moses.