Border Police detectives raided a home in the Arab city of Arraba in the Lower Galilee after receiving intelligence that illegal weapons were stored there.
A search of the home revealed eight firebombs on the home's roof, all of them ready for use.
An Arraba resident in his 40s was taken for interrogation by the Border Police.
On Wednesday, Israel Police's Prosecution Division will submit an indictment against the suspect for owning illegal weapons.