The transit officer saw the man rummaging through a trash can at Grand Central Terminal and saying he was looking for some socks.
And the big-hearted cop did something about it, with a random act of kindness.
A Facebook post by an observant commuter is bringing a lot more attention to officer Frank Rendina than he's used to.
On Friday Rendina, part of the NYPD Transit Bureau's Anti-Terrorism Unit, spotted a man digging through the trash on the 4/5 subway platform at Grand Central.
It was 70-year-old Ron Brown, a homeless man Rendina had come to know.
He asked Ron what he was looking for and Ron said socks, special socks to help with his diabetes.
Rendina, right there and then, not thinking anyone was watching, offered to buy socks for Ron as a Christmas present.
Joshua Lagan was watching - so impressed he wrote a lengthy Facebook post.
The post got the attention of Police Commissioner James O'Neil, who tweeted how proud he was of the NYPD and all New Yorkers.
"It was just being nice to someone that needed something, it wasn't anything outstanding, it was a couple of bucks," said Officer Rendina. "It wasn't anything outrageous. It was someone who needed something and couldn't afford it. I was able to do it."
Sometimes it's the little things in life.