Enclosed in this document is the account of Mr. Johnathan Crewes, who was recently incarcerated in the Psychiatric Ward, of how he was driven insane. He shall be soon shipped to the St. Josephine Asylum for the Mentally Disturbed.
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.