Mr. Abed said he was relieved when the Israelis brought another Red Crescent paramedic, Asaad al-Nasasra, still alive, over to the group of detainees. In handcuffs and a blindfold, Mr. al-Nasasra, whispered to him what he knew about their colleagues, Mr. Abed recalled.

Two looked wounded, one of them seriously, he said Mr. al-Nasasra told him. And last he had seen them, Mr. al-Nasasra recalled, two others were reciting the Shahada.

One Israeli soldier sounded triumphant when Mr. Abed asked about the other ambulance workers, he recalled. “Your colleagues — all of them are gone!” he told him, mockingly, in broken Arabic, the paramedic said.

“May God have mercy on their souls,” Mr. Abed recalled replying.

Another soldier told him, also in broken Arabic, that God had taken “those terrorists” to hell.

Eventually, the soldiers led Mr. al-Nasasra, the other paramedic, away. He is still missing, according to the Red Crescent.

That afternoon, Dr. al-Bardawil and Mr. Abed said they were asked to help the soldiers by telling a large group of civilians who had gathered in the area to evacuate the area. After they did so, they were released, they said.

Hurrying away, Mr. Abed left his jacket, ID card and bank card behind.

His parents had been panicking since they heard about the attacks.

“Reassure me you’re OK, dear son,” his mother, Somaya Abed, 49, had texted him at 7:52 a.m. that day, according to a message she showed a New York Times reporter.

There was no reply until Mr. Abed was released around 4 p.m. He called his father right away.

“I’m finally out and safe,” the younger Mr. Abed said.

But after hours of repeated beatings, he could barely walk, he said. A Red Crescent vehicle had to bring him home.