Hours after President Donald Trump banned millions of Muslims from U.S. shores, someone on Twitter brought up an old speech from an old president.

“Unifying,” he wrote. “Worth remembering.”

The speech maker’s daughter, Jenna Bush Hager, retweeted the comment. A few days later, Tuesday morning, she thought it was worth pasting the speech itself.

“‘This is not the America I know … ’” Bush Hager wrote, quoting former President George W. Bush’s speech at a mosque after the 9/11 attacks — amid a violent backlash against Muslims.

She tweeted: “‘This is not the America I know…’ just a reminder this am to teach acceptance and love to our kids for all races, all religions.. pic.twitter.com/32XohAGMv7”

Fifteen years ago, shoeless, her father had walked through the sanctuary of the Islamic Center of Washington.

It was six days after Islamist terrorists flew planes into the World Trade Center and the Pentagon, killing thousands. War plans awaited Bush back at the White House. But for six minutes that afternoon, he stood between an Islamic altar and a bank of TV cameras and admonished a country in fear.

“We’ve just had a wide-ranging discussion on the … ” Bush paused for a few moments. “On the matter at hand.”

Muslim men and women back-dropped the president. “Like the good folks standing with me,” he said, “the American people were appalled and outraged at last Tuesday’s attacks.”

He quoted from the Koran — “The English translation is not as eloquent as the original Arabic,” he said — and then addressed a wave of Islamophobia that had followed the terrorist strikes.

Dozens of attacks on Arab-Americans were reported that week, The Washington Post noted at the time. “Among them is the case of a Pakistani Muslim store owner who was shot and killed in Dallas Saturday evening.”

“I’ve been told that some fear to leave. Some don’t want to go shopping for their families,” Bush said at the mosque, and shook his head.

“Moms who wear cover must be not intimidated in America,” he said.

And then the line his daughter and many others would recall years later: “That’s not the America I know.”

The wars Bush launched in Iraq and Afghanistan would make him a divisive figure, at best, in the Islamic world throughout his presidency.

But years later, after he left office and anti-Muslim sentiment deepened in the United States, some would fondly remember that speech and the White House’s refusal to conflate Islamist terror groups with hundreds of millions of peaceful Muslims.

When President Barack Obama visited a mosque near the end of his presidency, The Post’s Aaron Blake reported, he took heat for it.

“Donald Trump said perhaps Obama ‘feels comfortable there’ — a comment thick with innuendo from a man who championed conspiracy theories about Obama’s birthplace,” Blake wrote.

Trump, of course, would go on to win the presidency after calling in a speech to ban all Muslims for the United States.

As Trump’s popularity grew, some members of the Bush family reportedly turned from their fellow Republican.

Bush’s other daughter, Barbara Bush, was photographed at a fundraiser for Hillary Clinton, and his father, former President George H.W. Bush, reportedly told a private gathering he would vote for the Democrat.

A spokesman for Bush declined to comment on the family’s reaction to Trump’s rhetoric about Muslims and his executive order last week, which barred visitors and immigrants from seven Muslim-majority countries.

“The same breathing room President Bush afforded to President Obama will be extended to President Trump,” the spokesman, Freddy Ford, wrote to The Washington Post.

On Twitter, Bush Hager explained why she quoted her father: “Just reinforcing his words that still, sadly pertain to today.”

She’s not the only one to think so.

On “Saturday Night Live” last month, the actor Aziz Ansari remarked on his sudden appreciation for the former president.

“What the hell has happened?” Ansari said in his monologue. “I’m sitting here wistfully watching old George W. Bush speeches.”