The political rally was winding down when the brash leader of a leftist South African party grabbed the microphone and began to stomp and chant. Thousands of supporters joined in, and when he reached the climax, they pointed their fingers in the air like guns.
“Kill the Boer!” Julius Malema chanted, referring to white farmers. The crowd in a stadium in Johannesburg on Saturday roared back in approval.
A video clip of that moment shot across the internet and was seized upon by some Americans on the far right, who said that it was a call to violence. That notion really took off when Elon Musk, the South African-born billionaire who left the country as a teenager, chimed in.
“They are openly pushing for genocide of white people in South Africa,” Mr. Musk, who is white, wrote on Monday on Twitter, the platform he now controls.
In recent years, people on the right in South Africa and the United States, including former President Donald J. Trump, have seized on attacks on white farmers to make the false claim that there have been mass killings.
Mr. Malema leads the Economic Freedom Fighters, a party that advocates taking white-owned land to give to Black South Africans. That has made his embrace of the chant all the more disturbing to some whites.
Despite the words, the song should not be taken as a literal call to violence, according to Mr. Malema and veterans and historians of the anti-apartheid struggle. It has been around for decades, one of many battle cries of the anti-apartheid movement that remain a defining feature of the country’s political culture.
The chant was born at a time when Black South Africans were fighting a violent, racist regime, and was made popular in the early 1990s by Peter Mokaba, a former youth leader in the African National Congress. But the A.N.C., the liberation party that has governed South Africa since the beginning of multiracial democracy nearly 30 years ago, distanced itself from the song in 2012 — the same year it expelled Mr. Malema for his incendiary statements.
Bongani Ngqulunga, who teaches politics at the University of Johannesburg, recalled struggle songs from the apartheid days in which people proclaimed they were going to march to Pretoria, the capital city, or that Nelson Mandela would be released from prison the next morning. The people singing those songs were not actually planning to march to Pretoria, nor did they really think that Mr. Mandela was about to be released, he said.
Similarly, he said, the phrase “kill the Boer” — the word means farmer in Dutch and Afrikaans — is not meant to promote violence against individual farmers. “It was a call to mobilize against an oppressive system,” Mr. Ngqulunga said.
Nomalanga Mkhize, a historian at Nelson Mandela University, said of the chant: “Young people feel that it rouses them up when they sing it today. I don’t think that they intend it to mean any harm.”
But John Steenhuisen, the white leader of the Democratic Alliance, South Africa’s main opposition party, filed charges this week against Mr. Malema at the United Nations Human Rights Council, and claimed, without providing evidence, that “brutal farm murders continue to escalate in the wake of Malema’s demagoguery.”
Analysts say that Mr. Steenhuisen is eager to placate white South Africans, who might be attracted to parties to his right, ahead of elections next year.
Mr. Malema, who thrives on provocation, projected a blasé attitude toward the criticism. “Bring it on small boy,” he wrote in a Tweet to Mr. Steenhuisen.
Asked during a news conference on Wednesday about Mr. Musk’s comment, Mr. Malema responded: “Why must I educate Elon Musk? He looks like an illiterate. The only thing that protects him is his white skin.”
Mr. Malema emphasized a court ruling last year that said he was within his rights to chant “kill the Boer.”
“I will sing this song as and when I feel like,” he said.
Just over a decade ago, a South African judge ruled that the song was hate speech and prohibited Mr. Malema, then the leader of the A.N.C. youth league, from singing it. But after being booted from the party and founding the E.F.F., Mr. Malema sang the song publicly again.
AfriForum, an organization that advocates for the interests of Afrikaners, descendants of South Africa’s white colonizers, took Mr. Malema to court.
Last year, Judge Edwin Molahlehi ruled that AfriForum had “failed to show that the lyrics in the songs could reasonably be construed to demonstrate a clear intention to harm or incite to harm and propagate hatred.”
“Before democracy, the song was directed at the apartheid regime,” he added, “and more particularly to the dispossession of the land of the majority of the members of the society by the colonial powers.”
Mr. Malema testified during that court proceeding that the lyrics should not be interpreted literally. The song, he told the court, was directed toward the government’s failure to address a disparity in land ownership between Black and white South Africans.
