A Thai mother rejoices at learning her son is alive.

Watsana Yojampa had been waiting by the telephone for nearly two months, wondering whether she would get good news — or the worst possible message that a mother could hear.

Soon after the Oct. 7 Hamas-led attack in the Gaza Strip, Ms. Watsana’s son, Anucha Angkaew, appeared in a photograph that circulated on social media showing him with three other men being held at gunpoint, hands behind their backs.

On Sunday at 4 a.m., Ms. Watsana got the phone call that she was waiting for. Her niece learned on X, the social media site, that Mr. Anucha, an avocado farmhand in Israel, had been released, and she called her aunt. Four hours later, Thai embassy officials confirmed the news to Ms. Watsana.

“I’m so glad, so delighted, that no words can explain,” Ms. Watsana said by telephone. “They told me that my son is now under the care of a medical team in a hospital for a health checkup. I hope he is fine and safe.”

Mr. Anucha was among four Thai hostages released on Sunday by Hamas as part of a swap with Israel. Thailand’s prime minister, Srettha Thavisin, said on Sunday that the other three were Natthaphon Onkaew, Khomkrit Chombua and Manee Jirachat. (Their names were written in Thai, and The New York Times transliterated them.)

Mr. Srettha said on X that all four men were healthy and not in need of urgent medical attention, and that their mental health appeared to be good. They asked to take showers and contact their relatives, according to Mr. Srettha.

Separately, the Thai Foreign Ministry said on Sunday that Israeli authorities had increased by two the number of Thai citizens they believe had been abducted. That means 18 Thai citizens are still being held hostage.

The Oct. 7 attack in the Gaza Strip has roiled Thailand, which more than anywhere outside of Israel and the Palestinian territories has borne the brunt of the war. The country is the largest source of foreign farm labor in Israel: More than 30,000 people from impoverished rural regions were working in Israel’s agricultural sector before the attack.

Thailand has pursued its own diplomatic campaign to get its citizens back. After the Thai foreign minister went to Doha, Qatar, on Oct. 31, Qatar began to work for the release of Thai captives in a separate mediation channel with Hamas, according to two officials briefed on the talks. Egyptian officials, who met with Thai officials, also helped negotiate.

Earlier this month, Ms. Watsana told reporters from The New York Times that Mr. Anucha’s 7-year-old daughter still did not know what happened to her father in Israel.

“Why are they hurting Thais; why are they kidnapping my son?” Ms. Watsana asked at that time. “We have nothing to do with their war.”

Pirada Anuwech contributed reporting.