Responding to accusations by the father of an American Muslim soldier killed in Iraq that Donald Trump has "sacrificed nothing", the billionaire said he had made many sacrifices, such as employing thousands of people.
KHIZR KHAN SPEECH IN FULL:
Tonight, we are honoured to stand here as the parents of Captain Humayun Khan, and as patriotic American Muslims with undivided loyalty to our country.
Like many immigrants, we came to this country empty-handed. We believed in American democracy - that with hard work and the goodness of this country, we could share in and contribute to its blessings.
We were blessed to raise our three sons in a nation where they were free to be themselves and follow their dreams.
Our son, Humayun, had dreams of being a military lawyer. But he put those dreams aside the day he sacrificed his life to save his fellow soldiers.
Hillary Clinton was right when she called my son "the best of America".
If it was up to Donald Trump, he never would have been in America. Donald Trump consistently smears the character of Muslims.
He [Trump] disrespects other minorities, women, judges, even his own party leadership. He vows to build walls and ban us from this country.
Donald Trump, you are asking Americans to trust you with our future. Let me ask you: Have you even read the US constitution? I will gladly lend you my copy. In this document, look for the words liberty and equal protection of law.
Have you ever been to Arlington Cemetery? Go look at the graves of the brave patriots who died defending America - you will see all faiths, genders, and ethnicities.
You have sacrificed nothing and no one.
We can't solve our problems by building walls and sowing division. We are stronger together. And we will keep getting stronger when Hillary Clinton becomes our next President.
Khizr Khan - whose son Humayun was killed at the age of 28 - accused the Republican presidential nominee of vilifying US Muslims, in a steely rebuke that electrified the Democratic Party Convention on Thursday.
"Go look at the graves of brave patriots who died defending the United States of America," Khan said, directly addressing Trump. "You will see all faiths, genders and ethnicities. You have sacrificed nothing and no one."
Trump, a property mogul and former reality TV star, brushed off Khan's words in an interview on Saturday with ABC News, stating that he thinks he has made "a lot of sacrifices".
"I work very, very hard. I've created thousands and thousands of jobs, tens of thousands of jobs, built great structures. I've had tremendous success. I think I've done a lot," the 70-year-old said.
Humayun Khan was killed by a suicide bomber in Iraq as he approached a car packed with explosives. Before enlisting in the army, he had planned to study law at university.
Trump suggested that Clinton's speechwriters penned Khan's emotional address.
"Who wrote that? Did Hillary's scriptwriters write it?" Trump said.
"If you look at his wife, she was standing there. She had nothing to say," Trump said, adding that "maybe she wasn't allowed to have anything to say".
Khan, though, said he wrote the speech with his wife Ghazala, who was standing beside him on stage in Philadelphia.
Among some of Trump's more controversial policy positions has been a call to ban Muslims from entering the United States.
Commenting on this, Khan said in his speech: "If it was up to Donald Trump, he [Humayun] never would have been in America," before challenging the nominee on whether he had read the constitution.
In his response, Trump did not say whether he had.
According to the US Department of Defense, more than 5,800 self-identified Muslims serve in the military.
After Trump's critique, Khan told ABC News: "Running for president is not an entitlement to disrespect Gold Star families and [a] Gold Star mother, not realising her pain. Shame on him! Shame on his family! ... He is not worthy of our comments. He has no decency. He is void of decency, he has a dark heart."
His wife Ghazala Khan said: "I am very upset when I heard when he [Trump] said that I didn't say anything. I was in pain. If you were in pain you fight or you don't say anything, I’m not a fighter, I can't fight. So the best thing I do was quiet."