John Gill Commentary Acts 7:33

"And the Lord said unto him, Loose the shoes from thy feet: for the place whereon thou standest is holy ground." — Acts 7:33 (ASV)

Then said the Lord to him

To Moses, who through curiosity had made too near an approach:

put off your shoes from your feet ;

in token of humility, obedience, and reverence:

for the place where you stand is holy ground ;

not really, but relatively, on account of the divine presence in it, and only so long as that continued.