In Parasha Yitro (Jethro) Israel arrived at the foot of the mountain prepared to ratify her covenant with God, but things didn't quite go as planned.
To understand what happened, it is necessary to start in Exodus 19.3-8. There we see God call Moses up to the mountain and give him a very precise script to read to the people of Israel. After an introduction, the script made an offer from God to Israel, "...if you will indeed obey my voice and keep my covenant, you shall be my treasured possession among all peoples, for all the earth is mine; and you shall be to me a kingdom of priests and a holy nation." In response to this offer, the people of Israel said, "All that the Lord has spoken we will do."
So there it is. A formal proposal and a formal response with Moses acting as the go between. In a very real sense, this was a betrothal with a formal ketubah (marriage contract) offered and accepted. At that point all that was required was for the two parties to meet and confirm the covenant. That meeting is the subject of Exodus 20.
In preparation for the meeting, Israel purified herself for three days and then assembled at the foot of the mountain - very much like a bride preparing for her wedding night. Indeed, the wedding metaphor is very good. Just as the marriage consummation is intended to plant a new life, at Sinai God intended and desired to place His word - which is life - within Israel's very heart. To see this, consider Jeremiah 31.33, "But this is the covenant that I will make with the house of Israel after those days, declares the Lord: I will put my law within them, and I will write it on their hearts." This is, of course, the New Covenant and it represents what God has wanted from the very beginning and was prepared to do at Sinai.
To understand what went wrong, it is necessary to understand what the 10 Commandments are - or what they are not. They are not orders in some sort of military sense, "Go there!", "Turn right!", "Carry that!", etc. Rather, they are statements of condition describing a people that is close to God. In that sense, it is impossible that someone in the very presence of God could be a liar. It is not conceivable that someone could be in proper relationship with God and commit murder. And so on. Said another way, "Do not covet" is not God telling one to refrain from something he desperately wants to do; rather it is Him saying, "When you are in my presence, you will not covet because you will realize that there is nothing else you could possibly desire."
This presented Israel with a serious problem. Standing in God's presence, all things were revealed; nothing could be hidden or kept secret; Israel was completely exposed by God's light of truth. Each Israelite, looking within himself knew that the things God as saying about him were simply not true.
Faced with the contradiction between what God was saying and the things she could clearly see while in His presence, Israel collapsed. "...the people were afraid and trembled, and they stood far off and said to Moses, 'You speak to us, and we will listen; but do not let God speak to us, lest we die.'" (Ex 20.18-19) The bride's heart could not receive the new life contained in the words of God. And so, the wedding night was called off - or rather put on hold - on hold for 3500 years so far.
Yet, the proposal was made and accepted and what God makes, He does not discard. So Moses once again went up the mountain and there he received tablets of stone with all of the words that God had wanted to write directly on Israel's heart. The tablets of stone signify that Israel has a heart of stone - as do we all. And so the Torah has been written in the wrong place for all these years. Yet God promises that this will not always be so. There will come a time when He changes our hearts from stone to flesh and then it will be as He has always wanted it to be.