Joshua 4:3-8

3and command them, saying, ‘Take twelve stones from here out of the midst of the Jordan, from the very place where the priests’ feet stood firmly, and bring them over with you and lay them down in the place where you lodge tonight.’” 4Then Joshua called the twelve men from the people of Israel, whom he had appointed, a man from each tribe. 5And Joshua said to them, “Pass on before the ark of the LORD your God into the midst of the Jordan, and take up each of you a stone upon his shoulder, according to the number of the tribes of the people of Israel, 6that this may be a sign among you. When your children ask in time to come, ‘What do those stones mean to you?’ 7then you shall tell them that the waters of the Jordan were cut off before the ark of the covenant of the LORD. When it passed over the Jordan, the waters of the Jordan were cut off. So these stones shall be to the people of Israel a memorial forever.” 8And the people of Israel did just as Joshua commanded and took up twelve stones out of the midst of the Jordan, according to the number of the tribes of the people of Israel, just as the LORD told Joshua. And they carried them over with them to the place where they lodged and laid them down there.