Musar for Sotah 67:6
עודם בירדן אמר להן יהושע הרימו לכם איש אבן אחת על שכמו למספר שבטי ישראל וגו' וכתיב (יהושע ד, ו) למען תהיה זאת אות בקרבכם כי ישאלון בניכם מחר לאמר מה האבנים האלה לכם וגו' סימן לבנים שעברו אבות את הירדן
It was to be a monument for the children that their fathers had crossed the Jordan. While they were still in the Jordan, Joshua said to them. Take you hence out of the midst of the Jordan, out of the place where the priests' feet stood firm, twelve stones, and carry them over with you, and lay them down in the lodging place, where ye shall lodge this night etc.<span class="x" onmousemove="('comment',' Josh. IV, 3. ');"><sup>11</sup></span> It is possible [to think that they were to deposit them] in any lodging place; therefore there is a text to state, 'Where ye shall lodge this night'.