Deuteronomy 1:6

The Lord our God spake with us (and not I, of my own mind) in Horeb, saying: It is enough for you, and hath been profitable for you until this time (during) which you have received the law, and have made the tabernacle and its vessels, and appointed your princes over you; but now it would be evil for you to tarry longer at this mount.

Ḥorev is Sinai, as I have explained [comment on Exodus 17: 9].

THE ETERNAL OUR G-D SPOKE UNTO US IN HOREB, SAYING. In my opinion Horeb was the name of a place near Mount Sinai where Israel dwelled in the year [of the exodus]. The wilderness was large and therein was the mountain which G-d hath desired; its name was Sinai and it is for this reason that the entire wilderness is called the wilderness of Sinai, as it were, “the wilderness of Mount Sinai.” Thus Scripture states, and they came to the wilderness of Sinai, and they encamped in the wilderness; and there Israel encamped opposite the mount,, Verse 2. meaning that they encamped in the wilderness in a place called Horeb, this being opposite the mountain. It is possible that both the mountain and the wilderness were called “Sinai” because many sneh (thorn-bush) trees were there, and near that mountain was a locality or an inhabited city called Horeb, and there they stopped. And the verse which states, and he [Moses] came to the mountain of G-d, unto Horeb, 3:1. [which might indicate that the name of the mountain itself was really Horeb or, perhaps, that the mountain was in the region called Horeb], means that he came to Horeb where the mountain of G-d was. Now the sneh (thorn-bush) [out of the midst of which the angel appeared to Moses] was on that mountain. Moses [at that moment] was in Horeb, the place before it, nearby, where the camp of Israel stood for [close to] a year [after the exodus]. Therefore Moses said, I will turn aside now and see [this great sight, why is the bush not consumed],, Verse 3. meaning that he will turn aside from Horeb [and walk] up to the mountain. At times Scripture calls the mountain itself [Horeb], as it is said, And the children of Israel stripped themselves of their ornaments from Mount Horeb,, 33:6. that is to say “from the mountain which was in the area of Horeb, in its vicinity or before it.” Or it may be that Horeb was the name of the entire region and the mountain was within it. Similarly, Remember ye the law of Moses My servant, which I commanded unto him in Horeb for all Israel, even statutes and ordinances, alludes to all that he was commanded on the mountain, and in the Tent of Meeting which was there in Horeb.
Now I have seen a Midrash in Yelamdeinu Rabbeinu: “Yea, thou knewest not … — at Sinai; yea, thou heardest not — at Horeb; yea, from of old thine ear was not opened — in the plains of Moab.” The Midrash thus intimates that Horeb is the place where the Tent of Meeting was, [thus confirming the view that Sinai and Horeb are different places]. However, Rabbi Abraham ibn Ezra states in Hebrew means “desolation,” or “dryness.” — This interpretation is found in Ibn Ezra’s commentary to Exodus 3:1-2. that Horeb is Mount Sinai, for, because of its desolation and dryness, the sneh (thorn-bush) grows there, so the mountain is known by two names [Horeb and Sinai], both being similar in meaning [“Horeb” referring to its desolate nature, and “Sinai” indicating the thorn-bushes that are products of the dryness].