Pun: in a certain language environment, using the condition of polysemy or homonymy of words, the sentence is intended to have two meanings, and the words here represent the other meaning. This rhetorical device is called pun.
"The home is clean and miscellaneous, and the virtual room is more idle." Dusty refers to mundane chores, and virtual rooms are quiet rooms. As an official, there are always a lot of stupid things that you don't want to do, and a lot of boring entertainment. Now I have got rid of all of them and lived a leisurely life in a quiet place. However, what makes the author most happy is not the leisure here, but that he can live according to his own wishes from now on.
"I've been in a cage for a long time, and I'm back to nature." Nature not only refers to the natural environment, but also refers to a natural and undistorted life. These two sentences once again echo the beginning of "not vulgar at all, naturally love autumn mountains", and at the same time point out the theme of "returning to the garden" But this kind of echo and direction does not feel reluctant at all. The whole poem, from the intense boredom of official life to the beautiful rural scenery and the joy of a new life, naturally reveals a feeling of relief. This ending is both exquisite and logical.