(לד) וַיְכַ֥ס הֶעָנָ֖ן אֶת־אֹ֣הֶל מוֹעֵ֑ד וּכְב֣וֹד יְהוָ֔ה מָלֵ֖א אֶת־הַמִּשְׁכָּֽן׃ (לה) וְלֹא־יָכֹ֣ל מֹשֶׁ֗ה לָבוֹא֙ אֶל־אֹ֣הֶל מוֹעֵ֔ד כִּֽי־שָׁכַ֥ן עָלָ֖יו הֶעָנָ֑ן וּכְב֣וֹד יְהוָ֔ה מָלֵ֖א אֶת־הַמִּשְׁכָּֽן׃ (לו) וּבְהֵעָל֤וֹת הֶֽעָנָן֙ מֵעַ֣ל הַמִּשְׁכָּ֔ן יִסְע֖וּ בְּנֵ֣י יִשְׂרָאֵ֑ל בְּכֹ֖ל מַסְעֵיהֶֽם׃ (לז) וְאִם־לֹ֥א יֵעָלֶ֖ה הֶעָנָ֑ן וְלֹ֣א יִסְע֔וּ עַד־י֖וֹם הֵעָלֹתֽוֹ׃ (לח) כִּי֩ עֲנַ֨ן יְהוָ֤ה עַֽל־הַמִּשְׁכָּן֙ יוֹמָ֔ם וְאֵ֕שׁ תִּהְיֶ֥ה לַ֖יְלָה בּ֑וֹ לְעֵינֵ֥י כָל־בֵּֽית־יִשְׂרָאֵ֖ל בְּכָל־מַסְעֵיהֶֽם׃
(34) The cloud covered the Tent of Meeting, and God's glory filled the Mishkan. (35) Moses could not come into the tent of meeting, because the cloud rested on it and God's glory filled the Mishkan. (36) [Later], when [God] raised the cloud up from the Mishkan, it [would be a signal] for the Israelites to move on, [and this was true] in all their travels. (37) When the cloud did not rise, they would not move on, [waiting] until the day it did. (38) God's cloud would remain on the Mishkan by day, and fire was in it by night. This was visible to the entire House of Israel, in all their travels.
Humility
The Mishkan, where the [Tablets] were housed, alludes to a Torah scholar. If a Torah scholar publicizes himself as the day is public, [God] will bring a cloud of obscurity over him. However, if a Torah scholar conceals himself like an object concealed at night, [God] will spread his fame as a fire is seen from a distance.
--Siach Yitchak (Rabbi Yitzchak Weiss of Verbau, Czechoslovakia who was killed in Holocaust in 1942)
Protection
According to tradition, the protective cloud that had accompanied the Israelites out of Egypt dissipated when the people worshipped the golden calf.... The people were confused; they felt vulnerable and abandoned due to [Moses'] absence, and they failed to appreciate that God's Presence was still very much with them in the form of the protective cloud. And because they turned a blind eye toward the ever-present manifestation of God, taking the cloud for granted, it was taken from them. This is the price to be paid for not appreciating God's protection: The protection is revoked. The cloud vanishes.
-- Rabbi Ari Kahn
Forgiveness
The true significance of the final verses of [Exodus]: The cloud has returned. For the first time, the people are granted a clear sign that the sin perpetrated at the foot of the mountain, the sin that had banished the cloud, has been forgiven. The cloud expresses the rekindled intimacy between the Jewish People and God. -- Rabbi Ari Kahn
Guidance
(טו) וַיַּ֥עַל מֹשֶׁ֖ה אֶל־הָהָ֑ר וַיְכַ֥ס הֶעָנָ֖ן אֶת־הָהָֽר׃ (טז) וַיִּשְׁכֹּ֤ן כְּבוֹד־יְהוָה֙ עַל־הַ֣ר סִינַ֔י וַיְכַסֵּ֥הוּ הֶעָנָ֖ן שֵׁ֣שֶׁת יָמִ֑ים וַיִּקְרָ֧א אֶל־מֹשֶׁ֛ה בַּיּ֥וֹם הַשְּׁבִיעִ֖י מִתּ֥וֹךְ הֶעָנָֽן׃ (יז) וּמַרְאֵה֙ כְּב֣וֹד יְהוָ֔ה כְּאֵ֥שׁ אֹכֶ֖לֶת בְּרֹ֣אשׁ הָהָ֑ר לְעֵינֵ֖י בְּנֵ֥י יִשְׂרָאֵֽל׃ (יח) וַיָּבֹ֥א מֹשֶׁ֛ה בְּת֥וֹךְ הֶעָנָ֖ן וַיַּ֣עַל אֶל־הָהָ֑ר וַיְהִ֤י מֹשֶׁה֙ בָּהָ֔ר אַרְבָּעִ֣ים י֔וֹם וְאַרְבָּעִ֖ים לָֽיְלָה׃ (פ)
(15) As Moses climbed the mountain, the cloud covered the mountain. (16) God's glory rested on Mount Sinai, and it was covered by the cloud for six days. On the seventh day, He called to Moses from the midst of the cloud. (17) To the Israelites, the appearance of God's glory on the mountain top was like a devouring flame. (18) Moses went into the cloud, and climbed to the mountain top. Moses remained on the mountain for forty days and forty nights.
(כא) וַֽיהוָ֡ה הֹלֵךְ֩ לִפְנֵיהֶ֨ם יוֹמָ֜ם בְּעַמּ֤וּד עָנָן֙ לַנְחֹתָ֣ם הַדֶּ֔רֶךְ וְלַ֛יְלָה בְּעַמּ֥וּד אֵ֖שׁ לְהָאִ֣יר לָהֶ֑ם לָלֶ֖כֶת יוֹמָ֥ם וָלָֽיְלָה׃ (כב) לֹֽא־יָמִ֞ישׁ עַמּ֤וּד הֶֽעָנָן֙ יוֹמָ֔ם וְעַמּ֥וּד הָאֵ֖שׁ לָ֑יְלָה לִפְנֵ֖י הָעָֽם׃ (פ)
(21) God went before them by day with a pillar of cloud, to guide them along the way. By night it appeared as a pillar of fire, providing them with light. They could thus travel day and night. (22) The pillar of cloud by day and the pillar of fire at night never left [their position] in front of the people.
Conclusion
The cloud does not blanket and obscure, as we expect clouds to do; instead, it is contained in a pillar and provides direction for the Israelites. Similarly, the fire does not spread and destroy whatever is in its path, as we expect fire to do; like the cloud, the fire is contained, giant torch. In both of these manifestations, the Israelites begin to see, just as Moses saw in the [burning] bush, the possibility of natural things, things of-this-earth, being bent and shaped in unnatural, divine ways....So it is for us: We need not be wary of looking for visual evidence of God's presence in the world around us. Seeking God's presence with our eyes is not idolatrous; it is only idolatry when we "know" in advance what we will see, when our expectations restrain us. Unfortunately, we may have been so afraid of making idols that we have limited ourselves to develop a relationship with God without using our eyes. What would happen if we started looking for God's presence in fire and clouds once more? How much do our relationships with God stand to gain from our actually seeing what may ahve been there all along? At the very least, we will benefit from the search alone, from our looking day and night. And at best, it is possible that if we look, we will see. --Rabbi Noa Kushner