Why Moshe had to remove his shoes whilst speaking to Hashem

I saw this idea in ‘Torah thought for a day’ – Shemos. (recommended!!) Moshe is told to remove his shoes as he will be walking on holy ground. It is known that in the times when the Bais Hamikdash was present, the kohanim had to remove their shoes. There are two reasons for this, the first behing that man must remove that ‘barrier’ between himself and G-d so that he can connect directly to the Almighty and feel His holiness. Other sources, such as the Kli Yakar explain that the removal of one’s shoes is a metaphor… In the presence of holiness one must try and remove all of his connections to wordly pleasures. Which leads to another reason why leather shoes arent worn on Yom Kippur – we have to remove that barrier and be completly subservient to Hashem… The maharshal brings down an idea that there are four levels of creation – lifeless objects (eg.stone, sand, etc), growing matter (eg. plants), living creatures and speaking creatures i.e. us, man. also, the maharshal brings down an idea that there are 4levels of creation: lifeless objects (eg.stone, sand,etc), growing matter (eg. plants), living creatures and finally, speaking creatures i.e. man. man shows his dominance over the lower levels of creation; man takes the skin of an animal making shoes for walking…whereas on Yom Kippur and Tisha B’Av, these are times when we should not be portraying this elevated status in order of creation, but rather…a servant of Hashem…