The Quba Mosque (Quba' Masjid or Masjid al-Quba, Arabic: مسجد قباء) just outside Medina, Saudi Arabia, is the first mosque ever built in Saudi Arabia and the oldest mosque of Saudi Arabia. Its first stones were positioned by the prophet Muhammad on his emigration from the city of Mecca to Medina and the mosque was completed by his companions. Muhammad spent more than 20 nights in this mosque (after migrating) praying qasr (a short prayer) while waiting for Ali whose house was behind this mosque.