Often parents will make the most extreme promises when their children are sick and they need a miracle. It is not uncommon to see an adult moving along the ground accompanied by a child, who is also acting out her devotion: parents promise to go to Rincón on their backs, dragging themselves, or crawling, and they promise to take their children with them if they survive. They go to pay their debt to the spirit who has delivered them.
Within the Afro-Cuban world, all things have their origins in the spiritual and historical precedents laid out in the odu, the divination signs that contain proverbs, formulaic advice, prescribed ceremonies, specific offerings, allegorical folktales, and myths. The idea of the promise was "born" in the odu Oché-Odí. It says, "El que paga su deunda queda franco--the one who pays his debt is free."
The odu also includes a story that details how devotion can change the attitude of the gods: in the land of Otá, Oyá was the queen, but she had an irrascible character. She was always moving from place to place. All her subjects feared her, especially when she manifested as Iyanzan, the tornado.
One day she was preparing an assault on the city of Ilofla, but a drunk started talking and the king there, Adé Koyí, found out. The king consulted the diviner and the sign Oché-Odí came, indicating a threat to the city. The diviner marked the ebó, the sacrifice, with two dark hens, nine pigeons, smoked fish and jutía (a marvellous rodent), palm oil, honey, black-eyed pea fritters, money, Oyá's special cloth called bayana, and her favorite caramel beads called matipó. The king offered the two hens to Oyá, the nine pigeons to nine different places in the city, and the rest of the ebó at the gate of the city. With the cloth and beads, he festooned the city walls.
When Oyá arrived at the city gate and saw everything decorated, she was pleased, and when she saw everyone doing her ceremonies, she was ecstatic and became the guardian of Ilofla. The citý's inhabitants continued to hang her special cloth on the walls as a sign of their loyalty.
From that time on, people offer bayaya cloth to Oyá to make her happy and it remains one of her favorite offerings.