That is putting the finger right on what happened to them and what they brought about in their lives. Suddenly, they felt naked, they felt exposed.
This act of covering themselves was a picture of self-righteousness. All attempts that man makes to hide his sin from God and to do away with his guilt are bound to fail. Self-righteousness only succeeds in fooling fellow human beings, and then not always. We cover ourselves with a fig leaf of good works which can hide our shame from human eyes, but it is not human eyes that really trouble us. It is knowing that God sees us, and even sees our feeble attempts to hide from him. Self-righteousness can never bring peace to the soul. How wonderful is the true covering that God supplies which convinces him and us that we are forgiven!