A diner's regular customer stunned the restaurant when he tipped the staff $3,000 on only a $39.60 check.

When the 12-person staff at Encounter Café in Bellevue, Washington received the generous gratuity, they originally thought it was a joke, until they saw the note left on the bill.

"You guys do a great job! When I was 7, I washed dishes and my mom cooked in a diner like this. We were dirt poor and didn't have money for Christmas. Hopefully, this will help all of you have a better Christmas," the customer wrote.

Eventually the diner's owner Melanie Bard figured out who the mysterious tipper was.

Bard said the extraordinary tip came from Dwayne Clark, the CEO and founder of Aegis Living, an assisted living community, who often frequents the diner with his wife on the weekends.

Clark, who has been dining at Encounter Café for the past eight years, told ABC News he wanted to "do something in appreciation of my mother, who's not with us anymore, and because of the Christmas season."

He said he remembers accompanying his mother to her shifts in the food service industry, and seeing how hard she had worked.  

"I saw how hard my mom worked for people who weren't always appreciative," Clark said, adding his mother was able to provide for him and his three siblings, and put them all through college.

According to Clark, the entire staff is well-deserving of the extra cash, especially during the holiday season.

"I eat there a lot and the people who work there have great attitudes, are really hardworking people," Clark told TODAY. "So when my wife returned to the restaurant from Christmas shopping, we just started talking about the meaning of Christmas. I got the check and I said, 'I think we're going to change some people's lives today.'"

As Clark requested, the staff will evenly split tip, and receive $250 each. He hopes his tip inspires others to be kind to one another.

"You don't have to give money. You can write appreciative notes and say thank you," Clark said. "It would go a long way to nourish all of us."

How will you be showcasing your Christmas spirit this holiday season?