Fairly early on in the story of Israel, something remarkable happens: God instructs Moses to write things down for the people.
In an age of widespread literacy like ours, especially at a time when almost all of our communication is written down in some form (many of us text instead of talking face-to-face, even), this doesn't seem all that remarkable. But when we think about the entirety of human history, we know that there were many eras when the written word was only for the learned. It was only for the elite. It was only for those who held positions of power in society and thus had been required to know how to read and write.
Almost everyone else depended upon the learned to tell them what the written word not only said, but meant.
Yet, here was God, giving His people a written word, and not just for them. This written word, He said, was to stay with them forever, being protected in the Ark of the Covenant for all generations of Hebrews to draw upon its wisdom.
But also, Israel was never to touch the Ark of the Covenant, so this written-down thing was to remain hidden in plain sight forever.
It's not unlike a contract that we may sign today. We enter into a contract, and we file it away. We put it somewhere safe because we know it binds us to the persons and the situations with which we signed it, but it doesn't govern our day-to-day. We do what we're supposed to do; we trust the other person to do what they're supposed to do. We only pull that contract out when we believe the other party has broken it.
Israel has never had a need to pull that covenant out of that box. Never.
That's what I think is so cool about the whole thing. God writes down this covenant for a people who might not ever be able even to read it, who would have to rely on someone else to even tell them what it says, let alone what it means, and then He goes on to be so good of a God that they don't need to read it anyway. They don't need to look at it. They can keep it tucked safely away in a box covered with mercy because there's just not ever a real concern that God is breaking it.
He is as good as He said He'll be. All the time.