You shall be to me a kingdom of priests and a holy nation.
Grace Before Law
The order at Sinai is everything. Before a single command is given, God reminds Israel what he has already done: 'You have seen... how I bore you on eagles' wings and brought you to MYSELF' (19:4). The law is not how Israel becomes God's people — they already are, rescued from Egypt by sheer grace. The commandments are the shape of a life lived in response to deliverance. Read in the other order, the Bible's law becomes a ladder to climb; read in this order, it is the contour of freedom.
A Kingdom of Priests
God's purpose for the nation is breathtaking: 'you shall be to me a kingdom of priests and a holy nation' (19:6). A priest stands between God and others; Israel is to be that to the whole world — a people through whom the nations come to know God. The vocation given at Sinai is the vocation Peter hands to the church: 'you are a chosen race, a royal priesthood' (1 Peter 2:9). Election is never for privilege only; it is for mission.
Thunder, Smoke, and Trumpet
The theophany is terrifying: thunder, lightning, thick cloud, a mountain wrapped in fire and smoke, a trumpet blast growing louder, the people trembling and kept back behind a boundary on pain of death. Sinai dramatizes the holiness of God and the distance sin has opened — the same God who bore them on eagles' wings cannot be approached carelessly. Hebrews 12 sets this scene deliberately against the new covenant: 'you have not come to a mountain that may be touched... but to Mount Zion... and to Jesus.'
The Ten Words
The commandments themselves fall into two tables — love of God (no other gods, no idols, the Name, the Sabbath) and love of neighbor (honor, life, marriage, property, truth, the heart's contentment) — which Jesus will gather into two: love God, love your neighbor (Matt 22:37-40). They begin not 'thou shalt' but 'I AM the LORD your God, who brought you out of the house of slavery.' The God who saves is the God who commands, and the order never reverses. The law given at the mountain is finally kept perfectly by the One who climbed another hill outside Jerusalem.
Go deeper: Berith — the covenant cut at Sinai (Lexicon) · Qahal — the assembly at the mountain (Lexicon) · Hesed — the steadfast love behind the law (Lexicon)