What causes the ironmaster to become angry with the peddler?

The ironmaster becomes angry with the peddler when he discovers that the man he mistook for an old acquaintance is actually a mere peddler, and he feels deceived. His anger intensifies when he learns about the peddler’s dishonest background, including the theft of thirty kronor from the crofter. This revelation shatters the trust and hospitality the ironmaster initially extended, leading him to feel betrayed. His frustration highlights the themes of identity and moral integrity, illustrating how quickly perceptions can change based on one’s actions and past.