Michael D Higgins grasped the hands of Guido Nasi as he welcomed him to Áras an Uachtaráin and shared with the Italian the "heartbreak" that the Irish people felt.
Guido and his mother, Simonetta, were guests at an event to mark the 25th anniversary of the Irish Tourist Assistance Service (ITAC).
It is almost 20 years since the then 17-year-old English language student was violently attacked in Dublin's Fairview Park, leaving him with catastrophic brain injuries.
The family was given assistance by the ITAC and during the event to mark the organisation's work, President Higgins deviated from his speech to deliver an unscripted tribute to the Nasis.
"I say to Guido, whose body was broken, and Simonetta whose heart must be broken, there are many people in Ireland who have been humbled by the sheer force of the forgiveness and love they have indicated."
He thanked Guido for retaining a positive view of Ireland "despite the grave harm that was done 20 years ago".
He added that the "terrible attack" was a message of how important it is to combat crime and said there was a great sense of "grief that this could happen in our country".
Guido, who lives in Turin and is unable to walk or to speak, has secured a publishing deal for his memoirs, which he has written using adaptive technology.
During his meeting with the President, he sought Michael D Higgins' advice on publishing.
Bernadette Kelly De Giorgi, who was the original volunteer assigned to Guido's case and has remained a family friend, said the book will be launched at a book fair in Turin later this year.
"He wanted to tell the President about his book and how he was hoping to have it published in Ireland so people could read it," she said.
In response, President Higgins, himself a published poet, recommended a leading, Italian-based translator.
Following the reception, Guido was anxious to convey a message to the Irish public. "Dublin and the people are in my heart," he communicated through hand gestures.
His mother Simonetta does not speak English, but her response to the event was universal: "Stupendo!" she told reporters.
The family plans to visit some other parts of Dublin later before flying home to Turin tomorrow.
