On March 5 in 702 B.C.E., the 16th year before Hezekiah’s death, a prominent solar eclipse appeared over the Middle East (according to NASA). Its path crossed the Arabian Peninsula, and the obscuration of the sun over Israel was more than 60 percent.
If a stairway had been engulfed in darkness and then restored to daylight, the shadow would have appeared to retreat. A shadow wave, produced by an eclipse, may also have given the appearance of a shadow retreating.
- BiblicalArchaelogy.org
ת"ר בשביל ארבעה דברים חמה לוקה על אב בית דין שמת ואינו נספד כהלכה ועל נערה המאורסה שצעקה בעיר ואין מושיע לה ועל משכב זכור ועל שני אחין שנשפך דמן כאחד
The Sages taught that on account of four matters the sun is eclipsed: On account of a president of the court who dies and is not eulogized appropriately, and the eclipse is a type of eulogy by Heaven; on account of a betrothed young woman who screamed in the city that she was being raped and there was no one to rescue her; on account of homosexuality; and on account of two brothers whose blood was spilled as one.
The Akeidas Yitzchak explains that solar eclipse really refers to the death of the righteous, the lights of our community who are extinguished. Yesod Olam goes in the other direction. He understands the four reasons for a solar eclipse as allegories for the movement of the moon. For example, the two brothers who die refer to the sun and the moon who both lose their light, so to speak, during a solar eclipse. Rema offers a different allegorical interpretation, connecting the four reasons to the movements of the astrological signs relating to a solar eclipse. - TorahMusings.com
Maharal (Be’er Ha-Golah, ch. 6, p. 106) explains that the Gemara is offering reasons why God established nature in such a way that there would be solar eclipses. If people did not sin, we would merit eternal light. However, because God knew people would sin, He created the world in such a way that solar eclipses would happen. - TorahMusings.com
Our Rabbis instituted blessings over acts of creation and powerful natural events, like lightning and thunder and so on. However, they did not do so for a lunar or solar eclipse. And if only today we could institute a blessing when we are aware that an eclipse is indeed an incredible natural event. But we cannot, for a person is forbidden to make up a blessing. If a person still wants to make some form of a blessing, he should recite the verses “And David blessed...blessed are you, G-d, the L-rd of our father Israel, who performs acts of creation.”
- R. Chaim Dovid HaLevi, Av Beis Din of Tel Aviv and Yaffo
it would seem that the most appropriate blessing upon witnessing a lunar or solar eclipse would be "Whose power and might fill the universe" ("עולם מלא וגבורתו שכחו ") It fits the criteria, most closely since the eclipse is a transitory event which is perceived over a wide area. Furthermore, even though most people do not perceive them as such today, eclipses were at one time considered a sign of danger
--The Blessing to Be Said Upon Witnessing a Solar or Lunar Eclipse, by Rabbi Joshua Heller
The Solar Eclipse Within
If you can observe it, recognize it and understand it, it must be found somewhere within you.
Yet more: Anything you observe is teaching you something about something inside of you. Something vital for your divine mission here on earth.
Yet more: The truth of each thing is the lesson it comes to teach you. Because if a thing enters your world, there could be only one reason: So that your soul could better fulfill the mission for which it is sent to this place.
If so, if there is anything you want to understand to its depths, you must first find it within yourself, and listen to what it is teaching you. And the Torah is your guide to finding it there.
So here’s the question of the day as the solar eclipse makes it’s way across America on August 21st, capturing a nation’s attention: Where is the solar eclipse within your life, and within your life’s mission?
the kabbalists tell us that the song of each being is its life-force, the divine energy that brings it into being and endows it with its nature.
Of what does the sun sing?
Of the time of its eclipse:1
The Sun is saying: “The sun, when covered by the moon, stood in its abode; they walk to the light of your arrows, and by the shine of your glittering spear.”2
Why would the sun sing about its eclipse? Let it sing about its great light, its warmth, how it makes possible all the life of our planet.
Rabbi Moshe ben Yosef deTrani (known by the acronym of his name “Mabit”) a halachist and kabbalist of Tzfat in the 16th century, explains:
The sun sings its praises to G‑d for the bad just as it does for the good. Even as it is struck by the moon standing before it, blocking its light, the sun remains in its place with all its light. It is only that the moon obstructs between us and that light.
The moon, on the other hand, is not that way. When the earth stands between it and the sun, it has no light, for all its light is from the sun
--Tzvi Freeman, Chabad.org