TSK · Exodus 18:5

Now Moses was keeping the flock of Jethro, his father-in-law, the priest of Midian, and he led the flock to the back of the wilderness, and came to God's mountain, to Horeb.

and be ready against the third day; for on the third day Yahweh will come down in the sight of all the people on Mount Sinai.

The glory of Yahweh settled on Mount Sinai, and the cloud covered it six days. The seventh day he called to Moses out of the midst of the cloud.