מדרש אויף שמות 30:36

2) The limitations: (Bamidbar 7:89): "And when Moses came to the ohel moed (for the L–rd) to speak to 1 him, that he heard the voice speaking to 2 him … and He spoke to him." (Shemoth 25:22): "And I will be appointed for you there, and I will speak to you … all that I will charge you with to the children of Israel." (Shemoth 29:42): "… where I shall appoint a time for you (plural) to speak to you (singular) there." (Shemoth 30:6):

6) — But let this exclude only Israel, who were not found fit to ascend Mount Sinai, but not the elders, who were found fit to do so! (viz. [Shemoth 24:1]: "And to Moses He said: Go up … and seventy of the elders of Israel.") Let it exclude the elders, who were not present at the L–rd's dibbur to Moses (on Mount Sinai after the giving of the Torah, viz. [Shemoth 24:14]: "Abide for us here," in the encampment, with the rest of the people), and not the sons of Aaron, who were present at the L–rd's dibbur to Moses. Let it exclude the sons of Aaron, who were not together with Moses for dibbur, and not Aaron, who was together with Moses for dibbur (viz.: "And the L–rd spoke to Moses and to Aaron" — and not to his sons). It is, therefore, written (Vayikra 30:6): "… where I shall be appointed for you" — For you there was appointment, but not for (any) of the others.

“And when Moses came into the Tent of Meeting to speak with Him, he heard the Voice speaking with him from above the Ark cover that was upon the Ark of the Testimony, from between the two cherubs; and He spoke to him” (Numbers 7:89).
“And when Moses came into the Tent of Meeting to speak with Him…” – one verse says: “And when Moses came into the Tent of Meeting to speak with Him…,” and one verse says: “Moses could not come into the Tent of Meeting…” (Exodus 40:35). It is impossible to say: “When Moses came,” as it is already stated: “Moses could not come.” It is impossible to say: “Moses could not come,” as is already stated: “When Moses came…” It is reconciled: “Because the cloud rested upon it” (Exodus 40:35). Say now: As long as the cloud was there, Moses would not enter there. When the cloud departed, he would enter to speak with Him.
Likewise it says: “The priests were unable to stand and serve due to the cloud, as the glory of the Lord filled the House of the Lord” (I Kings 8:11) – it teaches that permission was given to the angels of destruction to destroy. Likewise, it says: “I will cover you with My hand until I pass” (Exodus 33:22) – from here that permission was given to the angels of destruction to destroy. Likewise it says: “That I took an oath in My wrath that they would not come to My resting place” (Psalms 95:11)¹⁰⁹The midrash is interpreting the verse as though it says, “That I took an oath that in My wrath they would not come to My resting place,” which is different from the usual translation, "I took an oath in My wrath that they would not come to My resting place.” – but when My wrath abates, they will come to My resting place.
“Into the Tent of Meeting to speak with Him” – why is it stated? Because it says: “The Lord spoke to him from the Tent of Meeting” (Leviticus 1:1), I hear that it was actually from the Tent of Meeting. The verse states: “I will commune with you there and I will speak with you from upon the Ark cover…” (Exodus 25:22). It is impossible to say: “From the Tent of Meeting,” as it is already stated: “From upon the Ark cover.” It is impossible to say: “From upon the Ark cover,” as it is already stated: “From the Tent of Meeting.” In what way can both of these verses be realized? This is a principle of the Torah: Two verses, one opposing the other and they contradict one another, they remain in place until another verse comes and reconciles between them. Why does the verse state: “And when Moses came into the Tent of Meeting to speak with Him”? The verse tells us that Moses would enter and stand in the Tent, and a Voice descended from Heaven like a stream of fire between the two cherubs, and he would hear the Voice speaking to him, from within.
“To speak with Him” – Rabbi Yehuda ben Beteira said: Thirteen sayings were stated in the Torah to Moses and Aaron, and corresponding to them there were thirteen exclusionary phrases, to teach you that it was not stated to Aaron, but rather to Moses that he should say to Aaron. They are: “And when Moses came into the Tent of Meeting to speak with Him, he heard the Voice speaking with him…from between the two cherubs and He spoke to him.” “I will commune with you there and I will speak with you” (Exodus 25:22). “Where I will commune with you” (Exodus 30:36). “That I will speak with you there” (Exodus 29:42). “On the day of His commanding” (Leviticus 7:38). “What he would be commanded” (Exodus 34:34). “Everything that I will command you to the children of Israel” (Exodus 25:22). “It was, on the day that the Lord spoke to Moses in the land of Egypt” (Exodus 6:28). “These are the generations of Aaron and Moses on the day that the Lord spoke with Moses on Mount Sinai” (Numbers 3:1). “The Lord spoke to him from the Tent of Meeting, saying” (Leviticus 1:1). These are thirteen exclusionary phrases; it excludes Aaron from all of them.
Rabbi Yosei HaGelili says: In three places speech to Moses is stated in the Torah; in the land of Egypt, at Mount Sinai, and at the Tent of Meeting. In the land of Egypt, what does it say? “It was, on the day that the Lord spoke to Moses in the land of Egypt” (Exodus 6:28). It excluded Aaron from the speech in the land of Egypt. At Mount Sinai, what does it say? “These are the generations of Aaron and Moses on the day that the Lord spoke with Moses on Mount Sinai” (Numbers 3:1). It excluded Aaron from the speech at Mount Sinai. At the Tent of Meeting, what does it say? “The Lord spoke to him from the Tent of Meeting, saying” (Leviticus 1:1). It excluded Aaron from the speech at the Tent of Meeting.