in Islāmic mythology, the two-pointed magical sword that has come to represent Alīʿ, fourth caliph and son-in-law of Muḥammad. Originally owned by an unbeliever, al-ʿĀṣ ibn Munabbih, Dhū al-faqār came into Muḥammad's possession as booty from the Battle of Badr (624). He in turn passed it on to ʿAlī, and the sword, said to have borne an inscription ending in the words lā yuqtal Muslim bi-kāfir (“no Muslim shall be slain for 【the murder of】 an unbeliever”), eventually rested with the ʿAbbāsid caliphs.

As ʿAlī's legendary status grew, the importance of his association with Dhū al-faqār also increased. Particularly in legends surrounding the Battle of Ṣiffīn (Ṣiffīn, Battle of) (657), Dhū al-faqār, the two points of which were useful for blinding an enemy, is credited with enabling ʿAlī to perform phenomenal military feats, decapitating or cutting in half more than 500 men.

In Muslim countries, fine swords have traditionally been engraved with the phrase lā sayfa illā Dhū al-faqār (“there is no sword but Dhū al-faqār”), often with the addition wa lā fatā illā ʿAlī (“and there is no hero but ʿAlī”).