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.

I will be standing before you there on the rock in Horeb, and you will strike the rock, and water will come out of it so that the people may drink." And Moses did so in plain view of the elders of Israel.

So the Israelites stripped off their ornaments by Mount Horeb.