In the middle of winter, his wife writes him a letter. I have to plow our field to plant the potato crop, but the ox has died. I've buried there an entire cache of rifles and hand- grenades. Several days later, a truck-load of Russian soldiers descend upon the farm and furiously begin digging for the guns. Hours later, with nothing to show for it, they return to their truck and depart.
Every joke begins with a certain set of assumptions.
It develops a line of thought, builds our expectations, then suddenly hits us with a punch-line that overthrows all our previous notions. The absurdity of a sudden juxtaposition of a strange set of ideas casts the preceding assumptions in a new light and makes us laugh. This is true of all jokes. They proceed in a certain direction, until the twist at the end. Judaism teaches that everything in the world has at its core a spiritual truth.