A Snake On The Twelfth Moon Doesnt Bite

During the Sui Dynasty (581-618), there lived a clever man who spoke with a
slight stutter. Whenever the Minister Yang Su felt bored and listless, he would
invite this man over to have a chat. One evening toward the close of the year
when they sat facing each other, Yang asked him more in jest than in earnest: " Supposing you find yourself in a pit ten feet deep and ten feet in
circumference, how would you get out?"
The man lowered his head, meditating for some time, and asked: " Is there a 1-1-ladder?"
"No," replied Yang. " I wouldn't have asked you if there were a
ladder."
Again the man lowered his head meditating. Some time later, he inquired: " In br-br-broad daylight? Or at n-n-night?"
" No need to ask whether it's in broad daylight or at night," replied
Yang." The question is how would you get out."
" I'm not blind," reported the man. " If it isn't after
night-fall, how the hell could I fall into it?"
At that Yang burst out laughing and followed up with another question: " Supposing you were a general sent to a small city besieged by an enemy
tens of thousands strong. The garrison there numbered less than one thousand,
and the provisions would suffice only for a few days. What would you do?"
The man hung down his head, pondering over the problem for a long time. Then he
asked: " Any re-reinforcements for-forthcoming?" 
" No, " replied Yang, " that's why I asked you."
After muttering to himself for a good while, the man raised his head and said:
" If the situation is as you said, I'm afraid we're just about done
for."
At that Yang burst into laughter again and then put to the man the last
question: " I know you're a very capable man and there's scarcely anything you can't
do. It so happened that someone in my family got bitten today by a snake. Will
you see to the snake bite?"
" Well," said the man in response," go to the south wall and get
hold of some s-snow which fell on the fifth day of the fifth moon. Ap-apply it
to the bite, and he'll get well in no time." 
" But," protested Yang, " it never snows in the fifth moon."
" No," the man agreed. " In the twelfth moon, where can you find
a snake that bites?"
Much amused by his remarks, Yang Su let the man go.