Professor emeritus at The Hebrew University of Jerusalem, Department of Arabic Language and Literature. The principal focus of his scholarship has been on Jerusalem in Islam, the transition from Jahiliyya to Islam, and contemporary Sunni-Shia relations. His publications include: Fada’il al-Bayt al-Muqaddas of Abu Bakr al-Wasiti (1979); Le voyage de Sa’id ibn Muhammad al-Suwaysi au Yaman 1890-1895 (2008) (in collaboration with A. Arazi); “Muslim Literature in Praise of Jerusalem: Fada’il Bayt al-Maqdis,” The Jerusalem Cathedra, 1 (1981); “The Muslim View of Jerusalem—The Qur’an and Hadith” in J. Prawer and H. Ben-Shammai (eds.), The History of Jerusalem, The Early Muslim Period 638-1099, (1996); “Judham entre la Jahiliyya et l’Islam,” Studia Islamica (1995); “La conversion de Muawiya ibn Abi Sufyan,” JSAI (1998; “Les Shiites vus par les Neo-Wahhabites,” Arabica (2006).