|Sixteen Principal Odu|
Sixteen Principal Afa-du
Ifá is a West African religion and system of divination. Its literary corpus is the Odu Ifá. Orunmila is identified as the Grand Priest, as he is who revealed divinity and prophecy to the world. Babalawos or Iyanifas use either the divining chain known as Opele, or the sacred palm or kola nuts called Ikin, on the wooden divination tray called Opon Ifá.
Ifá is practiced throughout the Americas, West Africa, and the Canary Islands, in the form of a complex religious system, and plays a critical role in the traditions of Santería, Candomblé, Palo, Umbanda, Vodou, and other Afro-American faiths, as well as in some traditional African religions.
The 16 principle system seems to have its earliest history in West Africa. Each Niger–Congo-speaking ethnic group has its own myths of origin; Yoruba religion suggests that it was founded by Orunmila in Ilé-Ifẹ̀ when he initiated himself and then he initiated his students, Akoda and Aseda. Other myths suggest that it was brought to Ilé-Ifẹ̀ by Setiu, a Nupe man who settled in Ilé-Ifẹ̀. According to the book The History of the Yorubas from the Earliest of Times to the British Protectorate (1921) by Nigerian historian Samuel Johnson and Obadiah Johnson, it was Arugba, the mother of Onibogi, the 8th Alaafin of Oyo who introduced Oyo to Ifá in the late 1400s.  She initiated the Alado of Ato and conferred on him the rites to initiate others. The Alado, in turn, initiated the priests of Oyo and that was how Ifá came to be in the Oyo empire. Odinani suggests that Dahomey Kings noted that the system of Afá was brought by a diviner known as Gogo from eastern Nigeria. 
Orunmila came to establish an oral literary corpus incorporating stories and experiences of priests and their clients along with the results. This odu corpus emerges as the leading documentation on the Ifá tradition to become a historical legacy.
In Yorubaland, divination gives priests unreserved access to the teachings of Orunmila. Eshu is the one said to lend ashe to the oracle during provision of direction and or clarification of counsel. Eshu is also the one that holds the keys to ones ire, thus acts as Oluwinni (ones Creditor), he can grant ire or remove it.  Ifá divination rites provide an avenue of communication to the spiritual realm and the intent of ones destiny.
Among the Ewe people of southern Togo and southeast Ghana, Ifá is known as Afá, where the Vodun spirits come through and speak. In many of their Egbes, it is Alaundje who is honored as the first Bokono to have been taught how to divine the destiny of humans using the holy system of Afá. The Amengansi are the living oracles who are higher than a bokono. A priest who is not a bokono is known as Hounan, similar to Houngan, a male priest in Haitian Vodou, a derivative religion of Vodun, the religion of the Ewe.
There are sixteen major books in Odu Ifá  literary corpus. When combined there are total of 256 Odu (a collection of sixteen, each of which has sixteen alternatives ⇔ 16^2, or 4^4) believed to reference all situations, circumstances, actions and consequences in life based on the uncountable ese (poetic tutorials) relative to the 256 Odu coding. These form the basis of traditional Yoruba spiritual knowledge and are the foundation of all Yoruba divination systems. Ifá proverbs, stories, and poetry are not written down but passed down orally from one babalawo to another.
The Ifá Divination system was added in 2005 by UNESCO to its list of the " Masterpieces of the Oral and Intangible Heritage of Humanity". 
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-  Archived September 25, 2015, at the Wayback Machine.
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- Chief S. Solagbade Popoola & Fakunle Oyesanya Ikunle Abiyamo - The ASE of Motherhood ISBN 978-09810013-0-2
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