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.
This Torah we were given is not of the world, neither is it something extraneous to it. Rather, it is the hidden essence, the primal thought from which all the cosmos and each thing within it extends. It is not about the world, it is the world—the world as its Creator sees it and knows it to be.
The sages of the Talmud told us that the Torah is the blueprint G‑d used to design His creation. There is not a thing that cannot be found there.
Even more, they told us, the Torah is far beyond the world, beyond time, beyond any sort of being. G‑d and His Torah are one, for His thoughts are not extraneous to Him, nor do they effect any change in Him, as do our thoughts. Rather, His thoughts, His wisdom, His desire—all are a simple oneness that does not change.
But He took that infinite wisdom and condensed it a thousandfold, a billionfold, and more, into finite, earthly terms that we could grasp—yet without losing a drop of its purity, of its intimate bond with Him. Then He put it into our hands to learn, to explore and to extend.
So now, when our mind grasps a thought of Torah, thoroughly, with utter clarity, we grasp that inner wisdom. And when we are completely absorbed in the process of thought, comprehension and application, our self and being is grasped by that infinite wisdom which is the essence of all things.
We have grasped it, and it grasps us. In truth, we become that essence.