On this day, the bottom of Noah's ark, submerged 11 cubits beneath the water's surface, touched down and came to rest on the top of Mount Ararat.
(This follows the opinion of the Talmudic sage Rabbi Joshua, who maintains that the Flood began on Iyar 17.)
See: Great Flood Begins.
"Pulver Purim" was established by Rabbi Avraham Danzig (1748-1820) author of the halachic works Chayei Adam and Chochmat Adam, after he and his family were miraculously saved from a fire on the eve of the 16th of Kislev.
The inferno engulfed many homes, including his own home and the very room where all of his family members were, causing some of the walls to collapse. Rabbi Avraham Danzig then established the 16th of Kislev as a day of celebration for all of his future descendents.
In Torah, we mirror on earth that which G‑d performs on every plane of reality.
If so, since the Torah prohibits dislocating even a single stone of the Holy Temple in Jerusalem, how could it be that G‑d brought the entire structure to ruins?
For it would certainly be absurd to imagine that the Assyrians or the Romans had the power to set fire to G-d’s house.
It must be that this was not an act of destruction. Rather, it was the initial phase of a much greater construction, one that would be eternally indestructible.
And for that to occur, the Temple had to be temporarily leveled to its foundations and G-d’s people had to be scattered to the furthest reaches of human habitation.
Why? Because as long as there is any place in this world that considers itself outside the realm of holiness, there remains a place for the destruction of G‑d’s Temple.
But in our exile, we meet face to face all that considers itself foreign to the divine. We grasp its reins, extract its poison, and channel its power.
This third and ultimate Temple, then, will be built of the outside turned inward, of darkness taught to shine, of the other converted to the One, of the most sinister enemy transformed to a faithful ally.
No opposition will remain in the universe. And so it will last forever.
Then we will see that in truth, there was never any destruction. There was only rebuilding, growth, and eternal, deep love.