Christian concept? Ahhhh no.
By text I would assume you mean written. If this is the case i don't know of any. However there are oral traditions like the Akan or Vodun who have oracles that warn there people to keep non-Afrikans out of their socities and culture.
My question to you is how...
Mixing with non-blacks has NEVER been good for Black people and Afrikan culture. Traditional Afrikan societies have become a shell of their former selves as result of the adoption of foreign customs and mores.
Most Olorisha and Awos in the diaspora do not know Yoruba because they're religious. They tend to focus on rituals and oriki without overstanding the actual role of Isese.
Going to Nigeria for initiations having no knowledge and information about the people town or city they're being...
Be eni (yes) In fact there is no way other than casting merindilogun to ascertain what a divinity requires of you. On the website i provided there is an Ahosu (King) in the Vodun culture Daa Fawesagu who among other things performs Ipele Fa. He can do it without you being there.