Salman the Persian
The battle is named after the "trench", or "khandaq", that was dug by Muslims in preparation for the battle. The word "khandaq" () is the Arabised form of the Middle Persian word "kandag" (; meaning "that which has been dug"). Salman the Persian advised Muhammad to dig a trench around the city. The battle is also referred to as the "Battle of Confederates" (). The Qur'an uses the term "confederates" () in sura "Al-Ahzab" to denote the confederacy of non-believers and Jews against Islam.