In Israel, a prisoner of Zion is a Jew who was imprisoned or deported for Zionist activity in a country where such activity was prohibited. The phrase is taken from words of Rabbi Judah Halevi: "Oh Zion, will you not ask after the welfare of your prisoners." The former Speaker of the Knesset, Yuli Edelstein, and the former Chairman of the Executive of the Jewish Agency, Nathan Sharansky, were both prisoners of Zion in the Soviet Union.