Joshua 4
7 Ref then you shall tell them, Because the waters of the Jordan were cut off before the ark of the covenant of Yahweh; when it passed over the Jordan, the waters of the Jordan were cut off: and these stones shall be for a memorial to the children of Israel forever.
8 Ref The children of Israel did so as Joshua commanded, and took up twelve stones out of the midst of the Jordan, as Yahweh spoke to Joshua, according to the number of the tribes of the children of Israel; and they carried them over with them to the place where they lodged, and laid them down there.