Genesis 3:7 - The Popular Commentary by Paul E. Kretzmann

And the eyes of them both were opened, and they knew that they were naked; and they sewed fig-leaves together, and made themselves aprons. With their transgression, the eyes of the man and woman were indeed opened, but not in the way that they had supposed. The ignorance of primeval innocence was gone. Whereas they had not been aware of their nakedness before, they now felt shame before each other. Sin had corrupted and defiled their entire nature, like the poison of a serpent which penetrates into every part of the body with the circulation of the blood. In their painful embarrassment they sewed together the large leaves of the paradise fig tree for aprons to gird about their loins. Modesty or bashfulness naturally centers in this part of the body, requiring that the organs through which the impurities of the body are expelled, and which are now defiled for the service of indecency, be covered.