Why mention "the wilderness" in the opening of Bamidbar?

Question

The Torah says:

וַיְדַבֵּ֨ר יְהוָ֧ה אֶל־מֹשֶׁ֛ה בְּמִדְבַּ֥ר סִינַ֖י בְּאֹ֣הֶל מוֹעֵ֑ד -- The Lord spoke to Moses in the wilderness of Sinai, in the Tent of Meeting. [Numbers 1:1]

Ibn Ezra and others explain that the reason for specifying the location is to inform us that Moses did not have to go up to Mount Sinai to hear from God, as he did before, since God was now present in the Tent of Meeting.

But then, why not say just “in the Tent of Meeting” and omit “in the wilderness of Sinai”?

(There are other reasons in the Sources for mentioning the wilderness, but I want to focus on this one because it seems incomplete to me.)

Answer 1

The Ramban writes:

במדבר סיני בעבור שהפסיק במצות השמיטה והיובל, שהיו בהר סיני חזר ואמר כאן שהיה הדבור הזה באהל מועד, ככל המצוות אשר הזכיר מתחילת ספר ויקרא. וכן יהיו כלם מכאן ואילך: באהל מועד. כי מעת שהוקם המשכן: ויקרא אליו השם מאהל מועד לא מדבר לו אלא משם. והזכיר כאן במדבר סיני להגיד שלא נסעו משם בעת שנמנו, כי המנין השני היה בערבות מואב, והדבור באהל מועד.

AND THE ETERNAL SPOKE UNTO MOSES IN THE WILDERNESS OF SINAI, IN THE TENT OF MEETING. Because He had interrupted with the commandments about the Sabbatical year and the Jubilee, of which He said that they were spoken in Mount Sinai [in contrast to all the other commandments in the Book of Leviticus, which, as mentioned at the beginning of that book, G-d told Moses from the Tent of Meeting], He stated here again that this communication was given from the Tent of Meeting, as were all the communications which He had mentioned since the beginning of the Book of Leviticus. And all of them from now onwards [were said to Moses] from the Tent of Meeting, for since the time that the Tabernacle was set up and G-d called him [Moses] from the Tent of Meeting, He only communicated with him from there. Scripture mentions here in the wilderness of Sinai in order to tell us that they did not travel away from there until they were counted [the first time, as described here], for the second census was taken in the plains of Moab, but the [actual] communication was in the Tent of Meeting. (Sefaria translation)