From the Arabic root sh-h-d, lit. the act of bearing witness or the public declaration of belief. It is among the key principles of Islam. The shahāda has two parts: the first attests that ‘there is no god but God’; the second attests that ‘Muhammad is Messenger of Allah’ It is the second part that distinguishes Muslims from the followers of other monotheistic religions. When pronouncing the shahāda, Shi‘i Muslims often add the affirmation of Imam ʿAlī as the Commander of the Faithful (amīr al-muʾminīn).
