Updated at 2:05 p.m. ET.

When Jordan Smith got her tab after breakfast at Mary's Gourmet Diner in Winston-Salem, N.C., she was pleasantly surprised to find a 15 percent discount — for "praying in public."

Smith, on a business trip, tells HLN that she and her colleagues "prayed over our meal and the waitress came over at the end of the meal and said, 'Just so you know, we gave you a 15 percent discount for praying.' "

Smith then snapped a photo of her receipt, complete with a line item for "15% Praying in Public ($6.07)" and posted it to her Facebook page. Not surprisingly, it's gone viral.

Some people wondered if it was just another social media hoax, but the diner's own Facebook page appears to confirm it's for real. And many responded like Arlene Wilson Focht, who wrote on the diner's page:

Dave Moore was among those who questioned whether the restaurant would give the same discount to people who offered public prayers that weren't of the Christian variety:

Several others noted their interpretation that praying in public is frowned upon in the New Testament passage Matthew 6:5:

And some people wondered aloud if the restaurant's practice amounts to discrimination. The Department of Justice says that the Civil Rights Act of 1964 prohibits discrimination based on religion in a public accommodation, such as a restaurant. Whether the diner is in violation isn't immediately clear.

We put in a call to the DOJ for clarification and will update this post if we hear back. So far, we've been unable to reach Mary's Gourmet Diner.