Liamie Marum was heading home from work when he was approached by a homeless man asking for change for some food.
His first reaction was to say "No mate, I'm sorry I've no change", wrongly assuming the money was for drink or drugs.
However, after watching the man walk away he decided that this situation looked different.
Liam decided to follow 'Nathan' and buy him a burger in McDonald's.
He ordered a Big Mac meal. The customer assistant asked: "Would you like to go Large?". 'Nathan' looked at me and I smiled. I said, "Go ahead mate, no problem". He even had the manners to ask. Nathan couldn't stop saying "thanks" when receiving his €6.99 meal".
Liam explained: "Nathan told me he lost his brother two years ago and his sister took her own life over a month ago. He is now sleeping rough at the back of a school or college, in a sleeping bag!
"I asked Nathan if it was ok to take his picture and post it up here to bring to the attention of the public that, not all homeless people are junkies, or thieves or beggers...there are some who are genuinely suffering and need support."
The post published on Facebook has already been shared nearly 10,000 times.
Liam hopes that this small act of kindness can help people to be more understanding following some horrific stories about the recent treatment of homeless people in the city.