Exodus 3:6 English Standard Version (ESV) And he said, “I am the God of your father, the God of Abraham, the God of Isaac, and the God of Jacob.” And Moses hid his face, for he was afraid to look at God.

Nothing in Exodus 3 indicates what Moses did in that moment beyond hiding his face from God because of fear. The first impulse is to believe that Moses took off his sandals because he feared God at that moment. He was not told what to do with those sandals. There was no instruction to cast them back down the mountain or hide them.

If I place myself in that moment I can see how I might act but that is only my idea. I am not Moses, and Moses might have done something else. What is important about the sandals is not what Moses did but what I might do in that situation. 

Finding those sandals in my hands, fearing to even look at the face of God, what was meant to protect my feet are now used to shield my face from God. That is me, in a moment of understanding, this is how things changed when I came before God.

In the Garden Adam and Eve did not have sandals because there were no thorns or thistles to hurt them. It was not until they were ejected from the garden that they needed to protect their feet.

In my mind I see that if and when God releases me from His presence and I go back out into the world, I will need those sandals to protect my feet. I would not throw them away.

Now I see the sandals as things that are made by man to protect our walk in the world. Our feet are sensitive and our first point of contact in the world. What have we bought or made to protect ourselves as we make our way in the world? Remember the footwear is not provided by God, it is a thing of our own choosing.

Since this is a spiritual insight, then what do the sandals now represent as protective mechanisms to hide our pain?

Why pain? Because the thorns and thistles of the world are meant to cause us pain.