Exodus 3:5
Then he said, "Do not come near; put off your shoes from your feet, for the place on which you are standing is holy ground."
Joshua 5:15
And the commander of the LORD's army said to Joshua, "Put off your shoes from your feet; for the place where you stand is holy." And Joshua did so.
Ecclesiastes 5:1
Guard your steps when you go to the house of God; to draw near to listen is better than to offer the sacrifice of fools; for they do not know that they are doing evil.
2 Peter 1:18
we heard this voice borne from heaven, for we were with him on the holy mountain.