This is after he has been previously suspended from the knesset, for accusing Netanyahu of wanting a "final solution" for the Palestinians and for saying “All lovers of peace must join forces, Palestinians and Israelis, Arabs, Jews and the international community, and tell Israel to end the occupation now. (...) The Israeli government, which is a fascist government, supports, encourages, and leads pogroms against the Palestinians. There is an ethnic cleansing going on.”
Other members of the Israeli communist party have already been arrested for organising protests against the war.
https://hadash.org.il/english/
To be a pacifist in a country which maintains an occupation since 1967, to be supporters of democracy in a regime which advances eviction from lands and laws that trample on human rights, to implement a Jewish Arab partnership in a system which institutionalizes racism and discrimination in all spheres; to be the leaders of a struggle against a regime of privatization, and for the right of workers to unionize – this is a lifelong project.
A bit of a surprise they were still in up until this point