Féinnidi protected the community from invaders, from this world and the Otherworld.  When standing outside a ritual space modern Féinnid should do the same.  Here is a poem I wrote years ago for Pagan Spirit Gathering.  I would say it as the participants would process into the circle for the larger rituals.

Finn, Chieftain of the Fiana hear our call.
For we stand at the boundary between Order and Chaos, the civilized and the wild.
As the tribe gathers we come to observe and protect. 
We shall fear no man, nor beast, and nor spirit. 
We shall challenge any who come to do the people ill.
Gods and ungods of the people, know that we are here and we are allies.
With spear and shield we will protect the people, aid the people and sacrifice ourselves for the people.
We stand at the boundary between Order and Chaos, the civilized and the wild.

*Writing requirement for OOTW course *koyros1