Exodus 19:1-3

In the third month after the sons of Israel had gone out of the land of Egypt, on that very day they came into the wilderness of Sinai. When they set out from Rephidim, they came to the wilderness of Sinai and camped in the wilderness; and there Israel camped in front of the mountain. 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 sons of Israel