A team of archaeologists were excavating in Isreal when they came upon
a cave.  Written on the wall of the cave were the following symbols in
order of appearance

1.        A tomato 
2.        A donkey
3.        A shovel
4.        A fish
5.        A Star of David

They decided that this was a unique find and the writings were at
least three thousand years old.  They chopped out the piece of stone
and had it brought to the museum where archaeologists from all over
the world came to study the symbols.

They held a huge meeting after months of conferences to discuss what
they had decided was the meaning of the markings.  The president of
their society stood up and pointed at the first drawing and said,
"This looks like a tomato.  We can judge that this was a highly
intelligent race as they knew how to grow things to eat.  To prove
this statement you can see the next drawing resembles a donkey, so,
they were even smart enough to have animals help them till the soil.
The next drawing looks like a shovel of some sort, which means they
even had tools to help them.  Even further proof of their high
intelligence is the fish which means that had a famine hit the earth
whereby the food didn't grow, they would take to the sea for food.
The last symbol appears to be the Star of David which means they were
evidently Hebrews."  The audience applauded enthusiastically and the
president smiled and said, "I'm glad to see that you are all in full
agreement with our interpretations."

Suddenly a little old Jewish man stood up in the back of the room and
said, "I object to every word.  The explanation of what the writings
say is quite simple.  First of all, everyone knows that Hebrews don't
read from left to right, but from right to left.  Now, look again.  It
says 'HOLY MACKEREL, DIG THE ASS ON THAT TOMATO.'"