Assiah (or 'Asiyah, also known as Olam Asiyah, עוֹלָם עֲשִׂיָה in Hebrew, literally "the World of Action" and Aishah in Arabic) is the last of the four spiritual worlds of the Kabbalah —Atziluth, Beriah, Yetzirah, 'Asiyah— based on the passage in Isaiah 43:7.
According to the Maseket Aẓilut, it is the region where the Ofanim rule and where they promote the hearing of prayers, support human endeavor, and combat evil. Their ruler is Sandalphon. According to the system of the later Land of Israel Kabbalah, 'Asiyah is the lowest of the spiritual worlds containing the Ten Heavens and the whole system of mundane Creation. The light of the Sefirot emanates from these Ten Heavens, which are called the "Ten Sefirot of 'Asiyah"; and through them spirituality and piety are imparted to the realm of matter—the seat of the dark and impure powers.
Representing purely material existence, it is known as the World of Action, the World of Effects or the World of Making. In western occultism it is associated with the Suit of Pentacles (or Coins or Disks, the terminology varies according to the deck) in the Tarot. The world of Yetzirah precedes it.