(Bamidbar 7:89) "And when Moses came to the tent of meeting": (Why is this mentioned? We already know that the L-rd spoke to him from the tent of meeting.) From (Vayikra 1:1) "and the L-rd spoke to him from the tent of meeting," I understand directly from the tent of meeting. It is, therefore, written (Shemot 25:22) "And I will be appointed for you (to speak to you) there, and I will speak to you from above the kaporeth (the ark cover)."
It is impossible to say from the tent of meeting, for it is already written "from above the kaporeth," and it is impossible to say "from above the kaporeth," for it is already written "from the tent of meeting." How, then, are these two verses to be reconciled? This is a rule in the Torah: Two verses which contradict each other are to "remain in their place" until a third verse comes and reconciles them, (the third verse, in this instance, being) "And when Moses came to the tent of meeting."
Scripture hereby tells us that Moses would enter and stand in the tent of meeting, and the Voice would descend from the heaven of heavens to between the two cherubs (on the ark cover) and he would hear the Voice speaking to him from within. R. Yehudah b. Betheira says: Thirteen utterances were addressed to (both) Moses and Aaron, and, corresponding to these, thirteen "exclusions" (i.e., Aaron being excluded), to teach that they were not addressed to Aaron, but only to Moses to tell to Aaron.
They are; (Shemot 25:22) "And I will be appointed for you there, and I will speak with you, all that I shall command you," (Shemot 30:6) "where I will be appointed for you," (Ibid.) "to speak to you there," (Shemot 31:18) "to speak with him," (Vayikra 7:38) "on the day that he commanded," (Bamidbar 7:89) "And when Moses came to the tent of meeting to speak with Him," (Ibid.) "speaking with him," (Vayikra 1:1) "And the L-rd spoke to him," and one in Egypt (Shemot 6:28) "And it was on the day that the L-rd spoke to Moses in the land of Egypt," and one in Sinai (Bamidbar 3:1) "on the day the L-rd spoke to Moses on Mount Sinai," and one in the tent of meeting (Bamidbar 7:89) "And He spoke to him." — Thirteen exclusions, Aaron being excluded in all instances.