Peace-Holy

At the portal of the Crystal Moon in Jupiter orbit, Ruethen of the Long Hand says:

"'...while this log does burn upon the altar stone, peace-holy be it among us. As my tribe would say in the Cold Valleys.'"
-Poul Anderson, "Hunters of the Sky Cave" IN Anderson, Sir Dominic Flandry: The Last Knight Of Terra (Riverdale, NY, 2012), pp. 149-301 AT 1, p. 155.

Observations And Questions
It is better to burn logs than animals.
Ythrian Khruaths are also "peace-holy." See here.
Is "tribe":
another word for "Vach";
a sub-division within a Vach;
some other form of Merseian social organization?
We would like to know more about the Cold Valleys on Merseia.