In his article, Reflections on the Documentary Hypothesis, Kevin L. Barney wrote the following:
I do not intend here to undertake a complete study of the use of the various documentary sources in the Book of Mormon. It will suffice for me to offer one example of how the Documentary Hypothesis can help to make sense of something we find in that book. In 1 Nephi 17:29, Nephi is lecturing his brothers on the importance of keeping the commandments of God:
Yea, and ye also know that Moses, by his word according to the power of God which was in him, smote the rock, and there came forth water, that the children of Israel might quench their thirst.
This incident is recounted in completely positive terms and is almost certainly based on the E text of Exodus 17:6. P in Num. 20:1-13 gives the incident at the waters of Meribah a different spin. In this "anti-Moses" text, Moses fails to follow the Lord's instructions precisely (by striking the rock rather than speaking to it), and he and Aaron seem to take the glory of the miracle to themselves: "Hear now, ye rebels; must we fetch you water out of this rock?" (Num. 20:10, emphasis added). According to Num. 20:12, this incident became the reason the Lord refused to allow Moses to enter the promised land. Now, every Sunday school student is familiar with both the positive and negative accounts of Moses striking the rock; in fact, the 1981 LDS edition of the Book of Mormon cross-references both Exodus 17:6 and Num. 20:11. Yet Nephi and the Book of Mormon betray no knowledge whatsoever of the negative P tradition. I find this to be remarkable, and I take it as an indication that there may well be something to the Documentary Hypothesis. (p. 75)
I was reminded of Kevin’s discussion of JEPD and its relationship to this passage in the Book of Mormon today as James L. Kugel discusses Moses’ striking the rock in Num 20 and its relationship to Exo 17 in his most recent book. In the section “Moses’s Mistake,” Kugel writes about the text in Num 20:9-12 that:
This passage has posed something of a challenge to biblical interpreters in every period. Some have suggested that Moses had erred in striking the rock. After all, God had told Moses to speak to the rock, but He didn’t say anything about Moses hitting it with his staff-so he was punished. But this explanation seems unlikely on two counts. First, this wasn’t the first time that Moses was told to produce water from a rock. The same thing had happened years earlier, at the very start of the Israelites’ wanderings in the wilderness. On that occasion, too, there was not enough water for the people to drink; then as well, the people quarreled with Moses, and God instructed Moses to go to a certain rock with his staff.
[God said:] “I will be present there, next to the rock at Horeb, and you will strike the rock with your staff and water will come out of it for the people to drink.” And Moses did so in the sigh of the elders of Israel. (Exod 17:6)
Here there was apparently no problem with striking the rock: it gave up its water and God said nothing to Moses in the way of a reproach. So if there was no problem the first time, what was wrong the second time?
Those who blame Moses for striking the rock instead of talking to it have another problem as well. In the incident with which we began, no less than in the one just cited, God orders Moses to take his staff. What would be the point of such an order if all that Moses had to do was speak to the rock? What is more, the Hebrew word for “speak” (here dibbartem) seems to be connected to the same root that appears elsewhere as a verb meaning “strike” or “smash.” True, in the latter sense it is usually in the hiph’il (“causative”) form, but some scholars have suggested that dibbartem here may simply be an alternative to that form with the same meaning—that is, “strike.” After all, what sense does it makes for Moses to speak to a rock? At least hitting it is an action that might conceivable open some crevice through which water could then flow, perhaps from an underground stream beneath it. What would talking accomplish?
Considering such evidence, other commentators have ventured that Moses’s big mistake was striking the rock twice. After all, God had said nothing about striking it two times; if Moses had deviated from his instructions even in this one detail, wouldn’t that be enough to merit punishment? But this, too, seems unlikely. God’s instructions did not specify that Moses strike the rock any specific number of times; He certainly didn’t say “once and no more.” Even if Moses had struck it ten or twenty times, could that really be construed as disobeying God’s order?
Actually, I have never understood why this passage should seem so mysterious to commentators. The Bible states the reason for Moses’s and Aaron’s subsequent punishment quite clearly: “Since you did not show your trust in Me, sanctifying Me in the Israelites’ sight, you will not lead this congregation to the land that I am giving them.” What does this mean in context? It means that Moses should never have said what he said to the people: “Hear me now, you rebellious ones: can we get water for you from out of this rock?” The problem was the “can we get water” Through this little slip of the tongue, it seemed as if Moses and Aaron were actually taking credit for a miracle that God was about to perform and thereby not “sanctifying Me in the Israelite’s sight.” (James L. Kugel, The Great Shift: Encountering God in Biblical Times [New York: Houghton Mifflin Harcourt, 2017], 212-13, italics in original)