Abasil, home of the Wood Elves
Caladin, a country where people hate magic, where the sword is the most reliable weapon and where war and death not a uncommon word
A culture must hide its hands in the arm of their clothing as a sign of respect and peace. When approaching somebody you show them respect by crossing your arms and hiding the hands in the shirt sleeves. Nobody worries about hidden knives and such, it is the threat of magic that this custom was created to prevent.