Lost in Translation

פסחים מב.

אמר רב יהודה אשה לא תלוש אלא במים שלנו דרשה רב מתנה בפפוניא למחר אייתו כולי עלמא חצבייהו ואתו לגביה ואמרו ליה הב לן מיא אמר להו אנא במיא דביתו אמרי 

Pesachim 42a 

Rav Yehuda said: "A woman should only bake matzot with mayim shelanu."
Rav Matna taught this halacha to the people of Papunia. The next morning, the whole town knocked on his door.
"Give us some of your water!" they demanded!
"Why do you want our water?!" he asked them.
"You said, 'You must use mayim shelanu - our water - to make the matzot.' We would like some of your water to use to bake matzot like you taught us!" 
"No you idiots, not 'our water'! I meant mayim shelanu - water that was drawn the night before! 'Lanu' means 'slept', like the Aramaic word 'bitu'!"
"Ooooooooooooooooooooooooooohhhhh" the people of the town collectively said.

Amelia Bedelia would have fit right into this town. And if I had to guess, I would presume that Rav Matna was probably exceedingly elaborate when he taught classes in Papunia from then on.

Ribbi Yehuda b. Betera and the Greedy Arami

פסחים ג:

ההוא ארמאה דהוה סליק ואכיל פסחים בירושלים אמר כתיב (שמות יב) כל בן נכר לא יאכל בו (שמות יב) כל ערל לא יאכל בו ואנא הא קאכילנא משופרי שופרי אמר ליה רבי יהודה בן בתירא מי קא ספו לך מאליה אמר ליה לא כי סלקת להתם אימא להו ספו לי מאליה כי סליק אמר להו מאליה ספו לי אמרו ליה אליה לגבוה סלקא אמרו ליה מאן אמר לך הכי אמר להו רבי יהודה בן בתירא אמרו מאי האי דקמן בדקו בתריה ואשכחוהו דארמאה הוא וקטלוהו שלחו ליה לרבי יהודה בן בתירא שלם לך ר' יהודה בן בתירא דאת בנציבין ומצודתך פרוסה בירושלים

Pesachim 3b

There was was an Arami who would hang out in Yerushalayim around Pesach time and eat the korban pesach.
He would boast, "The Torah says, 'A non-Jew may not eat from it' and 'An uncircumcised person may not eat from it' yet I eat from the best of the best!"
Ribbi Yehuda b. Betera told him, "The best of the best, huh? Have they ever given you from the tail-fat?"
"....no." The Arami told him.
"They're just messing with you. They know you're not one of us. That's why they don't give you from the tail-fat, the best part of the sheep!" [In reality, the tail-fat gets burned on the mizbeach; any Jew at the time would know that.] Next time you go, ask them for some tail-fat!"
The next year, he asked for some tail-fat.
"Who told you to ask for tail-fat?" the people of Yerushalayim asked him.
"Your... um I mean OUR great sage, Ribbi Yehuda b. Betera!"
"This don't make no sense...." they said. They checked him and found out that he was an Arami. They responded by executing him. (Some say because גוי שגזל חייב מיתה, although it might have also been because they were pissed off at him for screwing with them all these years.)
They sent a thank-you message to Ribbi Yehuda b. Betera: "You reside in Netzivin, but your traps are set in Yerushalayim!"