Jessica Bell was riding the train home from work when she noticed the man's socks.

As CBS Chicago reports, Bell was transfixed by the sight of the homeless man sitting across from her on the CTA train. He was clearly old and suffering from exposure to the elements. But it was his feet that got her attention. As she wrote on Facebook:

His feet are so swollen he's wearing the tattered gym shoes he has with the back folded down, like slip-ons. I don't know how many pairs of socks he's wearing in an attempt to keep his feet warm but there is blood seeping through.

Bell wasn't the only one who saw the blood soaking through the man's socks. Maurice Anderson, a single dad taking the train home from the airport, also noticed ... and did something about it. Bell wrote:

There's another man on the other side of the doors; he's younger, carrying a satchel and a suitcase, also minding his own business. He's wearing a pair of big black snow boots. They look new; they look expensive; they're built for a Chicago winter.

Quietly, in a blink and you'll miss it fashion, the younger man takes off the boots he's wearing and passes them to the old man. He opens his suitcase and gives him a pair of socks as well.

Anderson was coming home from Kentucky, where he recently found work as an elevator technician. He returns to Chicago on weekends to see his daughter, so he happened to have an extra pair of shoes in his suitcase.

In the video below, the dad told CBS Chicago that he acted on instinct when he saw the stranger's feet:

“He was bleeding through his socks. So my gut said, 'Take [your boots] off and give them to him.' [...] He was overjoyed, and it actually gave me more joy to give it to him than anything.”

Anderson had no idea that someone had been watching and recording his act of kindness. He was mostly concerned with asking the man's shoe size (fortunately, they both wear a size 12), and getting his spare shoes out.

However, Bell and the others on the train were “floored.” She wrote:

The young man puts on a spare pair of shoes from the suitcase. These shoes are nice too, but not as nice as the boots. They would have fit the old man just as well, but they were not what this old man needed.

He tells the old man to try and clean his feet and to make sure he changes into the new socks as soon as he can and then the young man gets off at 87th.

The scene was so inspirational that Bell — who rarely posts on social media — was inspired to share it. And she hopes it will help others remember they have “the power to be a blessing.”

Bell runs her own charity providing homeless women with hygiene products, but the kindness in Anderson's gesture made a deep impression. As she told CBS Chicago:

“He literally, in the moment, took the shoes off of his feet and just handed them over. It was just so selfless. It was so quiet. It was so humble — was really what touched me about what Maurice did.”