The end of the Parsha and therefore the end of the Book of Shemot make reference to the “cloud” which covered the Tabernacle and the “glory of G-d” which filled it: “The cloud covered the Tent of Meeting and the glory of G-d filled the Tabernacle….For the cloud of G-d would be on the Tabernacle by day, and fire would be on it at night, before the eyes of all of the House of Israel throughout their journeys.” (Shemot 40:34-38)
Abarbanel explains that the “cloud of G-d” is a reference to the special ‘light’ which was created on the first day. The physical light which we experience today has its source in the sun and stars which were not created until the fourth day. The light of the first day was not of a physical nature and was ‘hidden away’ as it were, to be used by G-d for the benefit of specific individuals or groups at specified times. The Talmud in Chagiga (12a) relates that G-d saw that the wicked should not benefit from this light and He hid it away for the benefit of the righteous at a future date.
The ‘glory of G-d’ is a reference to this unique creation of the first day, and it is something similar to fire. The cloud is not the result of rising water vapor as are the clouds that we experience today; rather it is the entity which envelops and surrounds that light of the first day. This was the substance from which Noach received the promise that there would be no more floods; this was the pillar of cloud and this was the pillar of fire which accompanied the people when they left Egypt; this pillar and this cloud rested on Mt. Sinai in the eyes of the whole nation; this was the light that emanated from the skin of Moshe’s face when he descended from Mt. Sinai; this was the fire that burnt up Nadav and Avihu, the sons of Aharon, who offered an unauthorized sacrifice. Each time this ‘light’, which had been stored away at the beginning of creation, was put to use for a specific purpose.
In our Parsha this is the “glory of G-d” that fills the Tabernacle, which descends upon the altar and which was seen many times by the people at the entrance of the Tent of Meeting. This is what descended and filled the House of G-d that Shlomo built: “And the cloud filled the House of G-d and the kohanim could not perform the service because the Glory of G-d filled the House of G-d. (Kings I, 8:10-11). This was also the same fire that descended for Eliyahu during his confrontation with the priests of the idol ba’al on Mt. Carmel.
All of these examples are manifestations of that spiritual entity called ‘light’ which was created on the first day.