A Louisiana boy who gave his last dollar to a man he mistakenly thought was homeless was rewarded with a free shopping spree at a local sporting goods store, according to a report.

Kelvin Ellis Jr., 9, walked up to a man looking disheveled and tired outside a Baton Rouge coffee shop last month and offered him a $1 bill he had received for getting good grades.

It was the only money Kelvin had.

"If you're homeless, here's a dollar," Kelvin said, opening his hand to show a single bill. "I always wanted to help a homeless person, and I finally had the opportunity."  

The homeless man turned out to be the owner of the sporting goods store, BuckFeather, in Baton Rouge. 

Matt Busbice said he was moved by Kelvin's selfless behavior. 

"I haven't had that much faith in humanity in a very long time," Busbice told CBS News.

To repay the act of kindness, Busbice, 42, told Kelvin he could pick out whatever he wanted at BuckFeather for 40 seconds, including a brand new bike. 

Kelvin said he was appreciative but felt like he had already been repaid. 

He told CBS he felt "joy because I helped someone. Give something away, and you feel like you've got a lot of things from it."

Busbice said he and Kelvin initially came face to face while he was standing outside the coffee shop one morning when a fire alarm went off inside his condo complex and he jumped out of bed to see what was going on. 

Discovering there was no fire, Busbice, wearing mismatched clothes and looking a little scuffy, stopped by the shop to say his morning prayer and closed his eyes.

"I started to slowly open my eyes, and there's a kid coming at me, about my height," Busbice said. "And I go, 'What?'" 

"If you're homeless, here's a dollar," Kelvin said to him.