(CNN) -- The shoe attack on Iranian President Mahmoud Ahmadinejad in Egypt, the latest on a politician in the Middle East, causes many in West to ask: Why is throwing a shoe such a big deal?
One of CNN's resident experts is producer Mohammed Tawfeeq, who was in Baghdad when President George W. Bush dodged a flying shoe at news conference in the U.S. Embassy in December 2008.
Journalist Muntadhar al-Zaidi tossed it because he wanted to "humiliate the tyrant," his brother told CNN.
"Yes, I was there," Tawfeeq said. "It was a very big deal in Iraq."
In fact, some Iraqis celebrated that moment, he said.
"Other people were not happy because for them they see it -- by end of the day -- like a guest visiting their country," Tawfeeq said. "Traditionally, it was also offensive to insult a guest."
The act of throwing a shoe at someone or showing them your sole is "incredibly offensive" in the Middle East, he said.
"The bottom line is a shoe is dirt," he said. "Throwing a shoe on someone means throwing dirt on that person."
Professor Faegheh Shirazi, with Middle Eastern Studies at the University of Texas, agreed, saying it is offensive "regardless of the religious practices."
"Throwing a shoe or hitting someone with a shoe or showing the bottom of your shoe when sitting with legs up on a chair and facing another person all are culturally unacceptable and are considered to be a grave insult and belittling to a person," Shirazi said.
Another offensive aspect is the significance of the shoe being a sign of wealth.
"Most often, lower-status people and poor men could not wear shoes," Shirazi said. "The feet came in contact with pollution and the dirt on the road. The dirt on the feet indicated the lack of social status, the level of economic class and the level of education and lack of sophistication and intellect."
Tawfeeq, who occasionally visits the United States, was surprised to learn shoe throwing was not considered an offense in North America.
A search of literature reveals references suggesting the power of the shoe is ancient.
For example, in the King James Version of the Old Testament, Psalm 60:8 says: "Moab is my washpot; over Edom will I cast out my shoe: Philistia, triumph thou because of me."
"Perhaps it has to do with the hierarchy of the body position, that is, the relationship between the head and the feet, the head being at the top and not touching the ground and the dirt," Shirazi said. "The head carries a more prestigious status in comparison to the feet, which in older times mostly remained bare."