John Gill Commentary Deuteronomy 5:2

"Jehovah our God made a covenant with us in Horeb." — Deuteronomy 5:2 (ASV)

The Lord our God made a covenant with us in Horeb .
] Which is Sinai, as Aben Ezra observes; it being the same mountain, only it had two tops, which bore these different names; for certain it is that the decalogue after repeated was given at Sinai, and had the nature and form of a covenant; see (Exodus 24:7Exodus 24:8) .