Why did the ironmaster speak kindly to the peddler and invite him home?

The ironmaster of the Ramsjö Ironworks spoke kindly to the peddler because he had mistaken him for an old regimental comrade, Captain von Stahle.

The ironmaster wanted to help the peddler, not only in regaining his health but also in taking up a new vocation.  Moreover, the ironmaster was a lonely fellow who lived with his oldest daughter after the death of his wife and the departure of his sons. As he longed for some company on the Christmas Eve, he invited the peddler to his home.