Yehoshua (Joshua) 4:21-23

And he said to the children of Yisra’ĕl, saying, “When your children ask their fathers in time to come, saying, ‘What are these stones?’ then you shall let your children know, saying, ‘Yisra’ĕl passed over this Yardĕn on dry land,’ for יהוה your Elohim dried up the waters of the Yardĕn before you until you had passed over, as יהוה your Elohim did to the Sea of Reeds, which He dried up before us until we had passed over