Raed Salah, arrested on August 15, had his remand extended until Thursday, Khaled Zabarka said.
The 58-year-old Arab Israeli is accused of inciting violence and terrorism as well as support for an illegal organization.
Prosecutors told the court on Monday that they intend to file charges against Salah, Zabarka said.
Salah and his supporters call the accusations “political intimidation” intended to silent dissent.
His group, the radical northern branch of the Islamic Movement in Israel, was outlawed in 2015 for incitement linked to Haram Al-Sharif Mosque compound.
Police say the allegations against Salah include a sermon he gave after a July 14 attack that killed two policemen near Haram A-Sharif, which includes Al-Aqsa Mosque and the golden-topped Dome of the Rock.
Violence erupted in and around the site after two policemen were killed by security forces.
Israel responded to the July 14 deadly shootings by installing metal detectors at the entrance to the holy site, used as a staging point for the attack.
For nearly two weeks, worshippers refused to submit to the checks and staged mass prayers in surrounding streets.
Ensuing protests and clashes left seven Palestinians dead, while three Israelis were stabbed to death in a West Bank settlement by a Palestinian assailant.
The crisis abated when Israel removed the detectors.
The Jerusalem site is the third-holiest in Islam. It is central to the Israeli-Palestinian conflict.
Salah’s latest arrest follows his release from prison in January after serving a nine-month sentence on similar allegations.