According to the Mosaic law, an altar was to be built either of earth or of stones not "polluted" by any tools. (25) This injunction seems to have been necessary in order to save Israel from a tendency to make images, like those of the Egyptians, to worship. Their altars were not to be ornamented with heads of apes or dogs or snakes; they were to be built entirely of stones, as formed by nature, lest the worshiper might get the impression that he offered sacrifices to an image instead of Jehovah. The altar of Lehi was built of stones probably because he anticipated an extended sojourn in the Valley of Lemuel, by the River Laman.