Abu Ja'far, Imam Muhammad ibn Ali Al-Baqir عليه السلام, said to Abu Hamzah al-Thumali: "The four mosques are: the Sacred Mosque (Masjid al-Haram), the Mosque of the Messenger (Masjid al-Nabawi), the Mosque of Bayt al-Maqdis (Jerusalem), and the Mosque of Kufa. O’ Abu Hamzah, performing an obligatory prayer in any of these mosques is equivalent to performing a pilgrimage (Hajj), and a supererogatory (optional) prayer in them is equivalent to performing an ‘Umrah (minor pilgrimage)."