As soon as Mawu had created the Earth, she installed there the oil palm tree, De. This De was life itself, that is all that one may say. That is why it is associated with IFA, who is also life, existence. De was made Deputy by the Supreme Divinity, with full powers over all the Earth.
Man at this time, did not know of Mawu. If one desired to know something, one asked it of De, with his back turned to him, and he would be heard favorably. In these ancient times, neither man nor beast would die. De was naturally considered the Supreme Divinity, and as much as he was life. For everything in the palm was used in some way to sustain life, and the Holy ODU LosoChe [IrosunOse] tells us, de nu de ma ma gbe akwe, nothing of that which constitutes the palm is without value. Therefore, one takes the custom of using the term GBE de to express the idea of existence.
Meanwhile, the progress De made began to manifest on the Earth. The trees begin to grow, as did the vegetables. But man still did not know how to use fire to cook food. But De had children, the fruit (de kwi) and they ripened and fell to the Earth. Man collected them and ate them. He found them to be good. He extracted the oil from the pulp and used it to anoint the body and the bodies of humans glistened rightly.
Then, a hunter of the forest, being guided by De, discovered the Tree of Fire (zo ti). Yams were then washed and water and cooked in improvised hearth were found to be delicious. The hunter gathered everything new in the forest and there, where he found the fire, he encountered Aziza. He had long, scraggly hair, and only one foot. Aziza showed him why it is necessary to treat the nuts of the palm in order to extract the oil, and he taught him how to cook the yams in this oil. The hunter collected a little of this oil in a tugomaa leaf, rolled into a cone. Everyone found the oil delicious.
Aziza explained to him also why one prepares the delia, which is used with the tinderbox in order to capture the fire from its source in the forest and carry it to the family hearth. Such is, even until our day the reason for which the favi, the initiates in the worship of IFA carrie delia in the sacred box of IFA. Thus it is that the first humans know de as they're very Supreme Divinity, the tree of life, for to him they owed all. In order to see their Mawu, to find their kpoli, their soul, they must return to nature, to the forest, where the divinity hears them and where they exalt him just as in the time of their ancestors. And that is why he is named IFA zu vodun, Divinity of the forest. 
1. Maupoil, Bernard. The Ifa Oracle in West Africa. pg 7