(Sur). Fortress or rampart. The Fortress (sur) which the slave enters to gain Eternal Protection is 'There is no god other than Allah'. The Foundation upon which this Impenetrable Fortress is built is 'Allah'. The Door to the Fortress is 'Muhammad is the Messenger of Allah', and the Key to the Door is 'There is no power and no strength except in Allah'. The Foundation and the Fortress and the Door and the Key form the Noble Protection (Tahsin ash-Sharif) within which the slave of Allah is safe.