The central objective of the 19th of Kislev is that “your wellsprings should flow to the furthest places.” This is a calling to unite opposites, the deepest Divine knowledge should penetrate the lowest possible reality, the highest souls should become connected to the simplest, the Divine unit should be apparent in the material world.
This union of opposites is possible when the essence is revealed, for the essence is undefinable and can unite entities which are, by their definitions, mutually exclusive.
This is why chassidus was revealed to illuminate the darkness, and to prepare for Moshaich: for the litmus test to determine if this wisdom is truly the essence of the Torah is if it can reach the darkest place. Because it can illuminate the exile, therefore it is a taste of the essential revelation of Moshiach.
So, too, with Yaakov. The revelation of G-d’s transcendent “aloneness,” that He is one with everything, is when Yaakov refines and elevates even the smallest, lowliest jars. When Yaakov returns for those elements of creation, then the essence of G-d is revealed.
