Jon Polin says he has watched the video of his seriously wounded son being hustled into the back of a truck by Hamas gunmen countless times.
The scene played out just hours after 23-year-old Hersh Goldberg-Polin had spent time with his family on the last day of the Jewish holiday of Sukkot then spent the night dancing at a music festival with friends.
The youngster is just one of more than 200 people kidnapped by Hamas gunmen during their killing spree across southern Israel that began on October 7 and has left more than 1,400 dead.
After spending time with family, Goldberg-Polin had gone camping with friends at the Nova Music Festival and was there when the Hamas gunmen turned up and hurled grenades into a shelter where he and others had been hiding during the onslaught.
Footage later posted online shows the Israeli-American nursing his mangled arm which was blown apart near the elbow by a grenade blast, the remains wrapped in a bloody, makeshift bandage.
"That's a video that nobody ever wants to see of their loved one," his father said on Sunday.
"Despite that, I've watched it dozens of times, maybe hundreds of times," he added.
"In a really confusing way, I watch it and take strength from it," he said pointing to his son's ability to walk "on his own legs, on his own strength" -- which he attributes to "shock".
"I hope that he has the physical and mental fortitude to keep on fighting."
Sixteen days on and the family issued another plea for his release at a Jerusalem news conference, saying his condition was likely "dire" in the absence of medical treatment.
"It's a ticking time bomb," Amos Peyser, director of orthopaedics at Shaare Zedek Medical Center in Jerusalem, told reporters.
"This is an injury that we might say is... life threatening."
Goldberg-Polin's family pointed to the case of Yahya Sinwar, a Hamas leader who received medical treatment for a brain tumour while jailed by Israel in 2008.
"We're asking that it be reciprocated," said Polin.
The family's plea came just days after Hamas freed two Americans -- Judith Tai Raanan and her daughter Natalie Shoshana Raanan -- on Friday, following mediation efforts by Qatar.
Over the weekend, the Gulf state said it hoped to secure the release of more hostages soon.
"I can't promise you this will happen today or tomorrow... But we are taking a path that will very soon lead to the release of the hostages, especially civilians," said Qatari foreign ministry spokesman Majed Al-Ansari.
Following the Americans' release, a string of demonstrations were held in Europe and Israel over the weekend calling for more hostages to be freed.
The fate of the captives remains an open wound for Israel, with the government refusing to allow aid through its border into the besieged Gaza Strip until they are freed.
In the wake of the October 7 attacks, Israel has staged a withering bombing campaign against Gaza that has killed more than 4,650 people, mostly civilians, according to Hamas officials.
As the violence spirals, Goldberg-Polin's family said they were in touch with US President Joe Biden's administration but were still largely in the dark about what any backchannel negotiations might yield.
"We just want action," said his father.
"What's happening behind the scenes? I don't know. But I sure hope something is happening."
