You recognize the question as similar to the one Finnian asked when he first approached you. Clearly, it is some sort of secret code. Unfortunately, it is one you do not know the answer to. Before you can respond, Finnian offers the response from behind you.

"To wash away our sins," he says. "These are the Oathsworn, friends. They are here to help us."

Finnian motions for you to follow him, "Come, there is a place nearby where we can speak more privately. There is food and drink as well. I'm sure you have not had the chance to eat since arriving."