Joshua 4:4-7, 19-24

Then Joshua called the twelve men from the people of Israel, whom he had appointed, a man from each tribe. And 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, that this may be a sign among you. When your children ask in time to come, ‘What do those stones mean to you?’ then 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.”

The people came up out of the Jordan on the tenth day of the first month, and they encamped at Gilgal on the east border of Jericho. And those twelve stones, which they took out of the Jordan, Joshua set up at Gilgal. And he said to the people of Israel, “When your children ask their fathers in times to come, ‘What do these stones mean?’ then you shall let your children know, ‘Israel passed over this Jordan on dry ground.’ For the LORD your God dried up the waters of the Jordan for you until you passed over, as the LORD your God did to the Red Sea, which he dried up for us until we passed over, so that all the peoples of the earth may know that the hand of the LORD is mighty, that you may fear the LORD your God forever.”