Islamic mysticism or Sufism is one of the most outstanding appearances of Islamic culture that has had a fundamental and undeniable role in the history of Islam. A careful study of the history and development of the movements of Islamic culture shows that this movement, like most other ones, has been originated from, developed, and cultivated in an Islamic environment, though it has undoubtedly been affected by Hellenistic, Christian, Iranian, and other cultures in its historical process. The purpose of this article is to show the origin of Islamic mysticism and Sufism in Hadith through citing examples of some hadiths of the holy Prophet (s) and Imam ʿAlī (a) that clearly represent some mystical beliefs, methods, principles, and practices. It will be proved that in the early sources of Islam, especially in hadith sources, there have been abundant grounds for the emergence of Islamic mysticism and Sufism, without any need for other cultures. Proving this point, we reject the view that Islamic mysticism has originated from foreign cultures.