“The Israelis had no proof, and that’s why they’ve agreed to these four months,” she said in a telephone interview. “He’s shown by his steadfastness that we can be victorious.”
She laughed, and supporters could be heard ululating with joy in the background.
Mr. Adnan was arrested at his West Bank home on Dec. 17 and launched his hunger strike the following day.
He said he was protesting Israel’s policy of “administrative detentions,” in which it holds suspected Palestinian militants for months and even years at a time without charge. Mr. Adnan also claimed to have been beaten and humiliated in prison.
Israel has defended the policy of administrative detentions as a necessary tool to stop militant activity. It says the measure is needed to protect its network of Palestinian informants.
Mr. Adnan has been on three hunger strikes in the past. His sister Maali Musa said her brother undertook a 14-day hunger strike in 1999 after he was imprisoned by Palestinian authorities for hurling rotten eggs at officials during a demonstration.
He went without food for 28 days to protest his solitary confinement in 2005 when he was imprisoned by Israel. His sister said his strike forced Israeli authorities to return him to live with other prisoners.
He also undertook a 12-day hunger strike in 2010, again when he was arrested by the Palestinian Authority, which rules parts of the West Bank. Ms. Musa said her brother wasn’t charged with anything and quickly was released.
Mr. Adnan’s latest protest was the longest hunger strike ever by a Palestinian prisoner and caused some unease in Israel. The European Union and United Nations had expressed concern over the case and urged Israel to promptly give Mr. Adnan a trial.
There are some 300 Palestinians in Israeli administrative detention. They are a fraction of the some 4,200 Palestinians held in Israel, many who are doing time for charges ranging from throwing stones at Israeli soldiers to killing Israeli civilians.
Palestinians venerate the prisoners, viewing them as freedom fighters.
The second-longest hunger strike in Palestinian history was by a woman, Itaf Alayan, who refused food for 43 days before she was released in 1997. She was also an administrative detainee.