*whereas the light of the sun will be seven times greater than the light which was revealed during the seven days of Creation

I added the comment that the 6 days of sweltering blazing sun are kneged the 6 days of creation. The following article leads into that (in bold):

Shining Like the Sun
In times to come, both the sun and the moon will shine sevenfold.
From the teachings of Rabbi Shimon bar Yochai; translation and commentary by Moshe Miller

…to give light on earth. (Gen. 1:17)

Rabbi Yitzchak said: It is written, "The light of the moon will be like the light of the sun; the light of the sun shall be sevenfold the light of seven days." (Isaiah 30:26)

Which "seven days" are these? The seven days of Creation.

According to this view, the verse from Isaiah explains that the light of the moon which will be revealed in the future (see Zohar I, p. 45b; III, p. 93a) will equal the light of the sun now, *whereas the light of the sun will be seven times greater than the light which was revealed during the seven days of Creation. Accordingly, the moon will still be subservient to the sun.

Rabbi Yehuda said: This refers to the seven days of 'inauguration/miluim' [of the First Temple].

The moon…too will be a luminary….
Accordingly, in the future, the light of the moon will equal the light of the sun, and both will be sevenfold the light that was revealed during the inauguration of the First Temple. Accordingly, the moon will not need to receive its light from the sun, for it too will be a luminary.

Certainly [the verse refers to] the seven days of inauguration, for then the world will be completely rectified and the moon will return to its fullness without blemish [just as it was in the days of the First Temple]1

Note that the word miluim literally mans "fulfillment".

And when will this be? At the time of which it is written, "He will destroy death forever" (Isaiah 25:8) [and life will be eternal]. "On that day G‑d will be One and His Name One." (Zachariah 14:9)

Source: chabad: Kabbala online.
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With these 6 days of the heatwave, we are nearing the 7th Day:

• *whereas the light of the sun will be seven times greater than the light which was revealed during the seven days of Creation

Just one more day is needed, and this could refer to the Temple, possibly the Third Beis Hamikdash.