It tells that this process, from the vegetable to the animal, from the animal to man, is really the progress of the garb. For instance the first clothes were made of the bark of a tree. Then as people went on making clothes they found better materials and finally came to the forest. Man is the finest material: his garb, not his soul. His soul is the same as that of the man of a thousand years ago. The material has changed and has progressed with the evolution of the soul which has adorned itself with it. In this way the vanity of creatures has been made manifest. And as the matter of our bodies changes every few years, we attract a finer and finer quality of matter as we grow spiritually.