In the background of Joseph Smith it was customary for the river and the valley through which the river flowed to carry the same name; hence, the Mississippi River and the Mississippi Valley, the Missouri River and the Missouri Valley. However, this is not necessarily the practice in the Middle East, and it evidently was not the practice there 600 years B.C., as is indicated by the fact that Lehi named the river after his son Laman and the valley through which the river flowed after his son Lemuel. Concerning this practice of giving different names to valleys and rivers in the Middle East, Dr. Hugh Nibley has written:
By what right do these people rename streams and valleys to suit themselves? By the immemorial custom of the desert, to be sure. Among the laws "which no Bedouin would dream of transgressing" the first, according to Jennings-Bramley, is that "any water you may discover, either in your own territory or in the territory of another tribe is named after you." So it happens that in Arabia a great wady (valley) will have different names at different points along its course. . . .This confusing custom of renaming everything on the spot seems to go back to the earliest times. . . . Yet in spite of itsundoubted antiquity, only the most recent explorers have commented on this strange practice, which seems to have escaped the notice of travelers until explorers in our own times started to make official maps.
Even more whimsical and senseless to a westerner must appear the behavior of Lehi in naming a river after one son and its valley after another. But the Arabs don't think that way, for Thomas reports from the south country that "as is commonly the case in these mountains, the water bears a different name from the wadi." Likewise the Book of Mormon follows the Arabic system of designating Lehi's camp not by the name of the river by which it stood (for rivers may easily dry up), but rather by the name of the valley. (An Approach to the Book of Mormon [Deseret Book Co., 1964], pp. 65-66.)