Exodus 3:1

3:1 Now Moses was shepherding the flock of his father-in-law Jethro, the priest of Midian, and he led the flock to the far side of the desert and came to the mountain of God, to Horeb.

Exodus 3:5

3:5 God said, “Do not approach any closer! Take your sandals off your feet, for the place where you are standing is holy ground.”