By Abeer Salman, Ibrahim Dahman, and Oren Liebermann, CNN

(CNN) — Israel’s far-right security minister posted video footage of himself taunting the most high-profile Palestinian prisoner while visiting him in jail this week, in an encounter that has prompted outrage from supporters.

The video is the first time that Marwan Barghouti, 66, who is serving five life sentences after being convicted in 2002 for his role in planning attacks that killed five Israeli civilians, has been seen for many years. He appears gaunt and frail, with his arms held together in front as he nods slightly.

In the 13-second video, Itamar Ben Gvir taunts and threatens Barghouti, saying, “Whoever harms the people of Israel, whoever kills children, whoever kills women, we will wipe them out.”

Barghouti appears to try to respond, saying, “You know…” before Ben Gvir promptly cuts him off. “No no, you must know this, throughout all of history.” The video then abruptly ends. Ben Gvir posted the video on his Telegram channel on Friday morning.

Opinion polls have consistently shown him as the most popular Palestinian politician, and his time in prison has only increased the admiration in which he is held by Palestinians. Despite his life sentences, some see him as a successor to the ageing Palestinian Authority President Mahmoud Abbas.

Barghouti is only seen very rarely, and often years will pass between videos or images are seen by the public. Nevertheless, he remains hugely influential and is considered one of the few people who could unite Palestinian society behind a single leader.

On multiple occasions, Palestinians have tried to secure his release, including reportedly in ceasefire negotiations during the current war. But Israel has refused to consider releasing Barghouti.

The video ignited an almost immediate response from Palestinian officials, who condemned Ben Gvir’s message and Barghouti’s condition. Barghouti has been held in solitary confinement since the start of the war on October 7, according to his family and to the Palestinian Prisoners’ Society.

Barghouti’s wife, Fadwa Al Barghouti, said she didn’t recognize him at first and “maybe part of me doesn’t want to acknowledge everything that your face and body express,” she said in a post on social media.

“They are still, Marwan, pursuing you and following you even in the solitary confinement cell where you’ve been living for two years. The struggle against the occupation and its symbols with you continues, and the chains are still on your hands.”

A cousin of Barghouti told CNN that the video showed “something most awful,” adding that his relative looked “so thin” and “so weakened,” which he said was because his cousin is being “starved in his prison.”

When asked what Ben Gvir’s motivation to humiliate Barghouti might have been, Mustafa Barghouti said that the far-right minister “didn’t humiliate Marwan – he humiliated himself.”

“You can’t humiliate a person who is weakened by being put in a jail and in a cell,” he said. “In reality, he humiliated the Israeli government by this behavior.”

It’s unclear why Ben Gvir posted the video, which appears to be shot in a high-security prison in southern Israel where Barghouti is held. The far-right minister of national security is known for making provocative statements and served time in jail for anti-Arab incitement.

Palestinian Authority Vice President Hussein Al Sheikh called Ben Gvir’s threats “the height of psychological, moral, and physical terrorism practiced against prisoners, and a violation of international and humanitarian conventions and norms.”

Raed Abu Al-Humus, the head of the Palestinian Authority for Prisoners and Released Prisoners’ Affairs, said he holds Ben Gvir “fully responsible” for the Barghouti’s life. He warned that the threatening visit was a “dangerous indication of the intentions” of Ben Gvir.