וְלֹא־יָכֹ֣ל מֹשֶׁ֗ה לָבוֹא֙ אֶל־אֹ֣הֶל מוֹעֵ֔ד כִּֽי־שָׁכַ֥ן עָלָ֖יו הֶעָנָ֑ן וּכְב֣וֹד יְהוָ֔ה מָלֵ֖א אֶת־הַמִּשְׁכָּֽן׃
At hindi makapasok si Moises sa Tolda ng Pagtitipan, sapagkat ang ulap ay nanatili sa ibabaw nito, at pinuspos ng kaluwalhatian ng Walang-Hanggan ang Tabernakulo.
Rashi
ולא יכל משה לבא אל אהל מועד AND MOSES WAS NOT ABLE TO COME INTO THE APPOINTED TENT — But another verse says, (Numbers 7:89) “And when Moses came into the appointed tent [to speak with Him then he heard the voice]”! There comes, however, a third verse and reconciles these apparently contradictory verses, for it says here כי שכן עליו הענן “For (or when) the cloud abode thereon (on the appointed tent)”. Hence you may say: so long as the cloud was upon it “he was not able to come into the appointed tent”, but as soon as the cloud disappeared he entered it and spoke with Him (Sifra, Braita d'Rabbi Yishmael 18).
Bekhor Shor
And the Presence of God filled the mishkan. Like "And the mishkan was filled with the Presence of God", and so too many verses where the words are reversed, as in "For they have come under the shade of my roof-beam" (Bereishit 19:8), meaning, "Regarding this, for they have come" - and so there are many. And for the honour of Heaven the words were reversed. For if it had said "And the mishkan was filled with the Presence", it would mean that the presence were contained within the mishkan which held it. Now, where it is written "And the Presence of God filled the mishkan", it means that the Presence is great and the mishkan is contained in its midst. And so too it says "And God called to Moshe from the tent of meeting" (Vayikra 1:1) - every place where the cloud is, Moshe was unable to enter without being called, for then he was given permission to enter. And so too it says at the giving of the Torah, "And Mount Sinai was all in smoke" (Shemot 19:18), and it is written after it "And God called Moshe to the top of the mountain, and Moshe ascended" (Shemot 19:20). Our rabbis explained: for each word, there was [first] a "calling" [to Moshe] - for this is the way of the world: to call a person when one wants to speak with them, that they should know that one is speaking to them.
Chizkuni
ולא יכול משה לבא אל אהל מועד, “and Moses was unable to enter the Tent of Meeting,” at the time he had erected it. כי שכן עליו הענן, “for the cloud of glory of G-d rested above it;” it did so immediately, to demonstrate G-d’s fondness of the Jewish people. Subsequently, the cloud moved from being above the Sanctuary and took up its position above the Holy Ark which stood in the Holy of Holies. We know this from Exodus 25,22, where the Torah wrote: ונועדתי לך שם ודברתי אתך מעל הכפורת, “I will meet with you there and I will impart to you from above the cover of the Ark.”“Then Moses could enter the Sanctuary;” this is what is meant when the Torah wrote: 'ובבא משה אל אהל מועד וגו, “and when Moses used to enter the Tent of Meeting;” (Numbers 7,89). When Solomon consecrated his Temple something similar occurred as reported in Kings I 8,11. The priests were not able to enter and perform their duties as long as G-d’s cloud was hovering above the Sanctuary. Subsequently, that cloud was visible only above the Holy of Holies.