(Arabic; lit.: ‘pond of Khumm’): Name of a pool (or marsh) located in an area called Khumm between Mecca and Medina, in present day Saudi Arabia. Ghadir Khumm is famous in Muslim history as the location where the Prophet Muhammad, while returning to Medina from his farewell pilgrimage to Mecca in 632 CE, stopped to deliver a sermon during which he uttered the famous words declaring Imam ‘Ali as the mawla (lit. patron, lord, master) of the believers. These words are preserved in hadith collections as: ‘He whose mawla I am, ‘Ali is his mawla’. This event, which falls on 18th of Dhu’l Hijja in the Muslim lunar calendar, is commemorated by all Shi‘a Muslims as Eid (‘Id) al-Ghadir.