For Mahamed Jama, a Minnesota taxi driver, the Islamic restriction on drinking alcohol is a seamless rule for life.
"He who carries alcohol, he who drinks and he who sells it are the same thing," he says.
That belief could affect his livelihood.
The commission that runs the Minneapolis airports in May began enforcing a new policy allowing it to revoke the licenses of drivers who refuse to ferry passengers carrying alcohol - something that has happened to 4,854 travelers trying to get a cab at Minneapolis International Airport in the last five years.
"The increased penalties appear to have brought drivers into compliance," airport spokesman Patrick Hogan said of the policy - a 30-day license suspension for a first infraction and a two-year license revocation for a second.
Although Hogan said the measure was implemented without incident, it has provoked outrage among some of the 900 cab drivers who work the airport. About three quarters of them are Somali, most of whom are Muslim.
"A few of them are really, really upset about it," said Omar Jamal, executive director of the Somali Justice Advocacy Center in neighboring St. Paul. "They believe they have been forced into something against their faith, something against their religion."
Nevertheless, Jamal's group does not support the stand taken by the drivers. "We don't understand why they do this," he said. The issue is really "a process of getting adjusted to new territory, new culture."
Ahmed Rehab, executive director of the Chicago office of the Council on American-Islamic Relations, said the drivers are using a "strict and rigid" interpretation of Islamic law.
But Stephen Cooper, former commissioner of the Minnesota Department of Human Rights, said the change from the previous policy, in which drivers refusing a fare went to the back of the line, is unwarranted.
"Five or six times a month, somebody will get the second or third cab, rather than the first cab," Cooper said. "That seems pretty minor."
Culture clashes involving Muslims have been relatively rare in the United States, where Muslims are only a small fraction of the country's 301 million people.
A recent Pew Research Center study estimated there were about 1.4 million U.S. Muslims age 18 and over, though this figure is debated. The same report also found Muslims were "largely assimilated (and) happy with their lives."
The Minneapolis-St. Paul area, with its big Somali concentration and a Muslim community of 150,000 people out of a total population of 3.5 million, has seen its share.
Recently, Muslim clerks at a Target Corp. store refused to handle pork products, such as bacon, at check-out counters.
A spokeswoman for Target, which operates more than 1,500 stores in 47 states, said the company has a policy of accommodating such religious beliefs and said there was no indication the pork handling issue was a nationwide concern.
Minnesota has the nation's first Muslim representative in the U.S. Congress, but Democrat Keith Ellison has not been vocal on such issues since going to Washington last year.
Grappling with the issue of alcohol is a new phenomenon to many U.S. Muslims, said Abdi Ismail Samatar, a University of Minnesota professor, adding that Somali and other Muslim immigrants may not have even encountered alcohol before.
"When I was growing up in East Africa in a Muslim community, I heard of alcohol but I never (saw) what it looked like until I came to the United States," he said.
In a statement on its Web site, the Islamic Center of Minnesota seems to offer believers contradictory advice. It notes that the Koran prohibits believers to "sell, carry or profit" from alcohol, but adds that in "certain situations" Muslims may "do things which are forbidden based on the doctrine of necessity."
Samatar said that deciding how to interact with people who drink alcohol is a personal decision that each Muslim immigrant must make.
"There is a lot of soul-searching going on in the United States, not so much for drinking because that is forbidden completely, but how you relate to people who do so," he said.
It is a "personal interpretation (of the Koran) more than anything else."
Eltayeb Osman, a Muslim cabbie from Sudan, has negotiated his own rules for driving passengers who carry alcohol. He'll do it, but with certain restrictions.
"Put it in the trunk, put it in your hand, whatever," Osman said. "I don't need to touch it myself."