What Does Exodus 19:3 Mean?

While Moses went up to God, the LORD called to him out of the mountain, saying, "Thus you shall say to the house of Jacob, and tell the people of Israel." The first Sinai ascent initiates the covenant formation sequence: Moses goes up, YHWH calls and speaks, Moses is the message-bearer between the divine and the covenant community.

The "house of Jacob" and "people of Israel": using both the patriarchal name (Jacob) and the national name (Israel): is the address that connects the Sinai covenant to the Abrahamic-patriarchal covenant. The God who promised Abraham, Isaac, and Jacob is now speaking to their descendants at the mountain where his covenant will be formally established.

The "thus you shall say" (koh tomar) and "tell" (tagged) formula is the prophetic relay structure: Moses does not create the covenant terms but transmits them. The Sinai covenant has YHWH as its author, Moses as its communicating agent, and Israel as its recipient. The prophetic relay structure of the Sinai covenant is the model for all subsequent prophetic communication in the Old Testament: "thus says the LORD" is the prophetic formula derived from "thus you shall say to the house of Jacob." Every prophet who speaks "thus says the LORD" is functioning in the Moses-pattern established at Sinai.

The "house of Jacob" address to the nation immediately before the covenant's formal terms is theologically deliberate: the covenant being offered at Sinai is the fulfillment of promises given to Jacob/Israel at specific turning points of the patriarchal narrative (Genesis 28:13-15, Bethel; Genesis 35:10-12, Bethel renewed). The family that became a nation in Egypt is now being addressed as "the house of Jacob" at the moment of covenant formation: the family-promise is being fulfilled at the national-covenant level.