Musar do Jozuego 5:15

Exodus 3,5, tells Moses to remove both his sandals, whereas in Joshua 5,15, we find the latter commanded to remove only one of his sandals. Why? There are three differences in the two stories. A) Moses is asked to remove "your sandals," i.e. plural. B) Here we read that the earth Moses stands on is holy, i.e. אדמת קודש. In the book of Joshua the word "soil," אדמה is missing. C) In the book of Joshua, it is reported that Joshua complied, i.e. ויעש כן, he did so. This comment is missing in the case of Moses.