In May 1618, the Bohemian Revolt broke out in Prague, triggering the Thirty Years’ War. In November 1620, King Ferdinand II suppressed the rebels in Prague in the Battle of White Mountain. Notwithstanding the widespread looting, the king gave orders that no Jew be harmed. To commemorate the miraculous turn of events, R. Yomtov Lipman Heller, rabbi of Prague, instituted penitential prayers to be said every year on the 14th of MarCheshvan, which he published in Prague later that year. (The above account was recorded by R. Yomtov in his introduction to the publication.)
Where the Infinite Light is hidden
—there you see a world.
If you could see the light that generates this world
You would not see any world at all.
And yet the world you see
is nothing more than G-d's own hand hiding His light.
That is all there is to your world:
G-d hiding behind Himself.
Why?
So that you will search for Him
and find Him in this world of yours.