Комментарий к Бамидбар 33:49

מבית הישמת עד אבל השטים [AND THEY ENCAMPED] … FROM BETH-JESIMOTH EVEN UNTO ADEL-SHITTIM — Here it tells you that the extent of Israel’s camp was twelve miles, for Rabba bar bar Chana said: “I myself have seen that place etc., and it is three Parsangs (12 miles) square” (Eruvin 55b).

ויחנו על הירדן...בערבות מואב. There, וידבר ה' אל משה בערבות מואב על ירדן יריחו

ויחנו על הירדן מבית הישימות עד אבל השטים בערבות מואב, “they made camp by the river Jordan, from Bet Yeshimot until the plains of Shittim in the wilderness of Moav. The Torah describes the length of the camp, i.e. 12 “mils” (13,5 km.) We have the personal testimony of Rabbi Bar bar Chanah who was shown this site (Eiruvin 55). This is when G’d gave the direct order to disinherit (exterminate) the people residing in the land of Canaan at that time, as the people had now come very close to carry out this directive by crossing the river.