The opá iku is used when praying the moyuba (mojuba) to your ancestors, by tapping it on the ground to call up Egun to get present. While in the Yoruba homeland, the tapping of this staff members was pretty much performed on top of the graves of your buried ancestors https://stephenathtf.aboutyoublog.com/29661004/5-simple-techniques-for-la-rdc-aux-pays-suivants