From *The Skeptical Review*:
By Farrell Till
When the Israelites were camped in the wilderness of Sinai, Moses "went up unto God" (Exodus 19:3), which was no big deal in those days. People were always going up to God or God was coming down to them. Anyway, Moses went up to God and Yahweh called to Moses out of the mountain and said that he would make a "holy nation" out of the children of Israel (vs:5-6).
Such a prestigious honor, however, was not without its costs. Yahweh told Moses that he would come to him in a thick cloud that the people might hear when he spoke to Moses (v:9). Moses was then directed to "set bounds to the people round about" and tell them not to go up into the mount or touch the border of it. "Whoever touches the mount shall surely be put to death," Yahweh warned. "No hand shall touch him, but he shall surely be stoned or shot through; whether it be beast or man, he shall not live" (vs:12-13).
Now here's a thought for consideration. Let's suppose that there is an least an element of truth in the exodus tales and that at least a small troupe of Israelites did leave Egypt under the leadership of a man named Moses. What better way to keep them under control than to instill in them a fear and awe by telling them that they would suffer the divine wrath of their god if they intruded on sacred territory that was reserved only for Yahweh's chosen leader? I'm not saying that this actually happened, but indeed it could have. If Moses were such a charlatan as this, he could have minimized the risk of being discovered as a phony by making the people keep their distance when he was communicating with Yahweh or when Yahweh was speaking out of the cloud. A magician today wouldn't have any difficulty at all in making a cloud of smoke and then giving the illusion of someone speaking out of it. Maybe Moses controlled the people by such means as this. It's a thought that becomes very believable when one studies the "lest you die" warning that was so frequently used in the Pentateuch. Even the Kohathites who were chosen to bear the ark were warned not to touch the holy things in it "lest they die" (Num. 4:15). Why, if they touched the "holy things," they just might have decided that they were just ordinary objects with no special powers attached to them.
When I read "lest-you-die" passages in the Bible, it seems very likely to me that they were nothing more than scare tactics of priests who were just protecting their turf and reducing the chances that they would be found out for what they were, i. e., just ordinary men, by constantly warning the people that they would die if they came too close to the sacred paraphernalia that the priests used to bamboozle them.
Anyway, Yahweh presumably told Moses to put bounds on the people and warn them that they would die if they dared touch even the "border" of the mount. Then the omniscient Yahweh did a peculiar thing. He placed the same restriction on priests, who didn't even exist at the time: "And Yahweh said to him [Moses], Get down and then come up, you and Aaron with you. But do not let the priests and the people break through to come up to Yahweh, lest he break out against them" (v:24).
Now, really, what danger was there that the priests would break through to come up to Yahweh, because there were no priests at this time? It wasn't until chapter 28 that Aaron and his four sons were consecrated to be priests. That priests didn't exist until Aaron and his sons were set apart (28:1ff) is evident from 24:4-5, where Moses built an altar at the foot of the mount and appointed "young men of the children of Israel" to offer burnt-offerings and peace-offerings to Yahweh, and he himself took half of the blood, put it in basins, and sprinkled the other half on the altar. Then he took the blood in the basins, sprinkled it on the people, and said, "Behold the blood of the covenant, which Yahweh has made with you." The book of Leviticus is very specific in noting that such duties as these were reserved strictly for the priests, so why was Moses officiating at such a ceremony as this if there were priests who had been set apart to do it?
The logical conclusion is that the writer of Exodus made a boo-boo and put an anachronism into the text.