Exodus 19:1-3

In the third month after the children of Israel had gone out of the land of Egypt, on the same day, they came to the Wilderness of Sinai. For they had departed from Rephidim, had come to the Wilderness of Sinai, and camped in the wilderness. So Israel camped there before the mountain. And Moses went up to God, and the LORD called to him from the mountain, saying, “Thus you shall say to the house of Jacob, and tell the children of Israel