Salvation Army has been struggling hard for its annual fundraising campaign. Generous people are filling the red kettles, which is actually a charity box located at several spots of Minnesota, including many stores and other venues in the Northland.

According to NBCNews, over the weekend a Minnesota couple anonymously dropped a personal check for $500,000 into a Salvation Army kettle that was located outside a grocery store in a Twin Cities suburb. 

The humanitarian organization had set up the emblematic red kettle for decades for the purpose of collecting donations. The generous couple who spent their lives on discarded food once  placed their donations outside a Cub Foods in Rosemount, Minn. - a town about twenty miles outside of Minneapolis/St. Paul. At that time, the kettle was guarded by the volunteers from the Rosemount Fire Department.

Salvation Army Northern Division spokeswoman Julie Borgen told NBC News that the firefighters were unaware and realized after hours about the generous contribution.

The check left by the couple is the largest single donation made at a red kettle in the Twin Cities area, as mentioned by Grand Forks Herald.

"We are simply stunned and honored to have received such a generous gift," Maj. Jeff Strickler, Twin Cities Salvation Army commander, said in a news release. "This is a true blessing and it could not come at a better time for the Salvation Army and the people we serve."

However, the Salvation Army reported that the couple wishes to remain anonymous. In a news release, the charity revealed the reason behind the donations.

"The anonymous donors say they made the gift in hopes of encouraging others to give as generously as they can, too. Also, they wanted to honor one of their fathers, who served in the trenches in World War I, and was always grateful to the Salvation Army Donut Lassies who brought soldiers free coffee and donuts. That simple act of kindness and comfort made a lasting impression and created a family legacy of supporting The Salvation Army."

The young couple revealed that when they were young, they often fed on discarded food from the local grocery store. And now by donating, they expect others to do the same and help the needy.

Normally the kettle collects an average of $30 an hour, but the $500,000 check broke the previous record for a single donation to the charity which was $25,000, as reported by Daily Mail. The donation contributed a big hand to achieve the Christmas campaign goal of $11.6 million.

A Salvation Army spokeswoman added: 'This couple has supported the Army before with large checks in kettles, but never anything close to this level.'

The anonymous couple, known only as St. Grand, has been donating $1,000 or more checks to the charity for the last five years.