Biden, 75, was leaving a movie theater with his granddaughter in Washington D.C., when he stopped to speak to the man Thursday evening, according to a tipster who alerted Politico of the encounter.
The exchange, which took place outside of an AMC theater in Georgetown, was captured by a bystander, said Paul Equale, who shared a picture of the moment on Facebook.
“Character is about what you do when no one is watching,” Equale wrote.
“I’m not exactly sure what he gave the homeless man, but he appeared to write something down,” he told the news station.
Equale’s post of the photo has since gone viral. As of Monday morning, it had been shared more than 117,000 times and “liked” by more than 171,000 people.