NEW YORK >> “Take me in, oh tender woman, sighed the vicious snake!”

Candidate Donald Trump would electrify crowds by reciting those lyrics from the 1960s song, “The Snake.” Now they have a White House imprimatur. Trump revived them from behind a presidential podium during a rally Saturday in Pennsylvania marking his first 100 days in office.

Trump delivered a thundering spoken-word performance of the dark song — written by social activist Oscar Brown Jr. in 1963 and made famous by singer Al Wilson five years later — as an allegory to warn of what he sees as the dangers of illegal immigrants and refugees allowed into the United States.

“People are coming in and we know what we’re going to have problems,” said Trump, who dedicated the recitation to Homeland Security head John Kelly and border patrol agents. “We have to very, very carefully vet. We have to be smart. We have to be vigilant.”

The chilling song tells the story of a kind-hearted woman who finds a half-frozen snake and takes it home after the serpent cries out “Take me in, oh tender woman, take me in for heaven’s sake.”

The woman nurses the snake back to health, whispering, “If hadn’t brought you in by now, you might have died,” only to be bitten by the venomous serpent. As members of the crowd mouthed the words along with the president, Trump then read the dramatic conclusion:

“I saved you,” cried the woman,

“And you’ve bitten me, heavens why?

“You know your bite is poisonous and now I’m going to die.”

“Oh shut up, silly woman,” said the reptile with a grin,

“You knew damn well I was a snake before you took me in!”

Trump’s warnings about the supposed dangers of immigrants were at the core of his campaign. But multiple studies have shown immigrants are less likely to commit crimes than native-born citizens.

Trump began reciting the sinister song at the occasional campaign rally last year. At first, especially when Trump would forget to explain or introduce it, the odd campaign moment was met with puzzled looks from rally-goers and journalists alike.

But as he began to do it more frequently and videos of the performances were posted on YouTube, the crowd would roar when he launched into it as if a favorite rock band was dusting off a greatest hit.

His performance in Harrisburg was the first time he recited it since he took office. Other presidents have quoted songs or poems before — John F. Kennedy had a fondness for Robert Frost — but experts believe “The Snake” is uniquely Trump and largely effective.

“It’s a pure Trumpian moment: the gestures, the facial expression, the joy of delivering the message are all prototypical Trump,” said Tobe Berkovitz, a communications professor at Boston University. “It dramatizes the message. It’s not just the message, it’s how the message is delivered and how the audience responds, like a chant of ‘Build the wall.’”

Trump often introduces the song as having been composed by Al Wilson, a soul singer who turned “The Snake” into a hit in 1968. But it was actually written earlier that decade by Oscar Brown Jr., a Chicago author, singer-songwriter and social activist, who drew inspiration from the ancient Aesop fable “The Farmer and the Viper.”

Brown died in 2005 and his family believes that Brown would be “pretty damn outraged” that Trump was using it as justification to shut America’s borders, according to his daughter Maggie Brown.

“Snakes bite and kill people. That’s not what all Muslims do. That’s not what all illegal immigrants do. This is dishonest and unfair not what my father would have meant,” said Maggie Brown, a Chicago-based songwriter.

But while they disagree with his interpretation, Brown’s family has far more mixed feelings about Trump’s use of the song. One daughter, Africa Brown, said she was “kind of thrilled” that Trump would recite it, saying she “couldn’t believe that one of the biggest figures in the media — who is now the president — is saying words my father wrote.” But Maggie Brown says she was “angry” and has called for Trump to stop reciting “The Snake.”

A White House spokeswoman did not respond to a request for comment about Brown’s request.

Trump has never said what drew him to use “The Snake,” but during the campaign he tended to perform when linking his warning about borders to a news event, like the Syrian refugee crisis or a terror attack. In some ways, the recitation was akin to the communication Trump conducts from his Twitter account: a direct, knowing appeal to supporters with no outside media interference.

“It’s effective for his target audience,” said Berkovitz. “The people who respond to it are Trump’s true believers and ‘The Snake’ is part of his gospel.”