Why does God warn Moses to not allow the priests or the people to approach Sinai?

Question

In Exodus 19, God describes a number of preparations that Moses should make before He will ascend to the top of Mount Sinai. One of them is to cordon off an area around the mountain:

You shall set bounds for the people round about, saying, ‘Beware of going up the mountain or touching the border of it. Whoever touches the mountain shall be put to death: o hand shall touch him, but he shall be either stoned or shot; beast or man, he shall not live.’ When the ram’s horn sounds a long blast, they may go up on the mountain.—Exodus 19:12-13 (NJPS)

But three days later, after God appeared on the mountain in fire:

The Lord said to Moses, “Go down, warn the people not to break through to the Lord to gaze, lest many of them perish. The priests also, who come near the Lord, must stay pure, lest the Lord break out against them.”—Exodus 19:21-22 (NJPS)

Naturally, Moses expresses some confusion:

But Moses said to the Lord, “The people cannot come up to Mount Sinai, for You warned us saying, ‘Set bounds about the mountain and sanctify it.’” —Exodus 19:23 (NJPS)

So why did the Lord tell Moses to warn the people not to come near a second time? The text doesn't seem to support the idea that the Lord forgot about the first warning, but that sort of seems like what Moses implied.

Answer 1

One reason for the redundancy is the unfaithfulness of the people. What we continually see in Exodus through Deuteronomy (interesting, huh, a second giving of the law) is that the people are incredibly unfaithful to God. There unfaithfulness is very repetitious; therefore God is repetitious in his commands. Plain and simple, they never listened the first time.

A second and possibly more important reason is the supreme holiness of God (his separateness, especially but not exclusively with regards to his righteousness). It is as in Isaiah 6, where he is pronounced thrice holy by beings who are themselves holy; or as in the Tabernacle, and later in the whole land of Israel, which was holy in itself but was more holy the closer one was to the seat of God's presence. In fact, throughout the book of the law there is a redundancy and seemingly ludicrous layering of ceremonies, all driving home the holiness of God. The endless repetition and impossibly burdensome nature of all the imperatives through the books of Moses serves to show the holiness of God.

Answer 2

My guess is that God saw that some of the people were about to violate the ordinance and approach the mount. This means they would be killed. In order to prevent that from happening, God sent Moses down to give them another warning, and displayed flashes of lightning to reinforce the warning, after which the people moved away from the mountain. The goal was not to prevent people from climbing the mount, but to prevent them from being killed as they tried to climb the mount. It seems that God believed an additional exhortation and more signs were necessary to save life.

Exodus 20:18 (KJV 1900)

18 And all the people saw the thunderings, and the lightnings, and the noise of the trumpet, and the mountain smoking: and when the people saw it, they removed, and stood afar off.

Answer 3

I apologise in advance if this interpretation offends some readers.

Exodus is a documented account, written or at least dictated by Moses, of the history of the Hebrew people's relationship with their God. It is not a comprehensive account of everything that happens in the settlement, so naturally it may be necessary to read between the lines on occasion in order to make sense of the text.

In this book Moses documents any conversation he has with God, to which, importantly, no one else is a witness. In fact, there are many precautions put in place, in the form of rules and regulations, prohibitions and ceremonies, supposedly all set by God through Moses, to ensure that he remains the only witness to God.

If you can picture how this would play out in the real world, with real human beings, you could also picture more than one or two people managing to sneak through the bounds in the hope of either witnessing God for himself or verifying the truth of what Moses has been saying.

Such 'unfaithfulness of the people' would force Moses to make this repeated assertion, through the relayed word of God, that the mountain was out of bounds, and that breaking through to try and see God would mean their death.

The apparent confusion expressed by Moses then comes across as feigning ignorance of any transgressions, thereby absolving himself of any deaths that may have happened to culprits.