Fast forward a few days and he has forgotten his oath, ignored the delivery, and sold the shirts to other vendors along the way... Then my husband wondered why he was shunned and forbidden from conducting any business in Ald'ruhn. The wrath of Zenithar is absolute!
He did eventually go back, find the shirts, and complete the quest, but not before I spent several weeks jokingly blaming every real-life annoyance (from a stubbed toe to telemarketers) on Zenithar's righteous anger.