Joshua 4:7-8

4:7 tell them how the water of the Jordan stopped flowing before the ark of the covenant of the Lord. When it crossed the Jordan, the water of the Jordan stopped flowing. These stones will be a lasting memorial for the Israelites.”

4:8 The Israelites did just as Joshua commanded. They picked up twelve stones, according to the number of the Israelite tribes, from the middle of the Jordan as the Lord had instructed Joshua. They carried them over with them to the camp and put them there.