Is the intention (Niyyah) obligatory for the validity of prayer?

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The intention is obligatory for the prayer to be established. The basis for this is the command of Allah the Almighty: 'And they were not commanded except to worship Allah, being sincere to Him in religion' (Quran 89:5). Sincerity is an action of the heart, which is the intention, denoting the singular will for Allah alone. Furthermore, the Prophet, peace be upon him, stated: 'Actions are only by intentions, and for every person is what he intended.' The intention means purpose, and its place is the heart. If the prescribed prayer (Fard) is intended, the intention must specify the exact prayer, such as Dhuhr or Asr, requiring the intention of both the act and its specification.