The Hassan II Mosque in Casablanca is one of two mosques in Morocco open to non-Muslims.

Under most interpretations of Islamic law, non-Muslims may be allowed into mosques, as long as they do not sleep or eat there. A dissenting opinion is presented by followers of the Maliki school of Islamic jurisprudence, who argue that non-Muslims may not be allowed into mosques under any circumstances.^[44]

The Qur'an addresses the subject of non-Muslims, and particularly polytheists, in mosques in two verses in its ninth chapter, Sura At-Tawba. The seventeenth verse of the chapter prohibits those who join gods with Allah — polytheists — from entering mosques:

It is not for such as join gods with Allah, to visit or maintain the mosques of Allah while they witness against their own souls to infidelity. The works of such bear no fruit: In Fire shall they dwell. (Yusuf Ali ^{[Qur'an 9:17]})

The twenty-eighth verse of the same chapter is more specific as it only considers polytheists in the Sacred Mosque, the Masjid al-Haram in Mecca: