יהושע טו:ד פירוש: רש״י

Extended. The end of the border was at the Great Sea,⁶The Mediterranean Sea. which is the western border of all of Eretz Yisroel. Thus the boundary of Yehudah occupies the entire length of Eretz Yisroel from east to west and is located in the south of Eretz Yisroel.