Step 1: Recalling the Text:
In Selma Lagerlöf's 'The Rattrap', the peddler, who had stolen thirty kronor from the crofter and was later treated with dignity and respect by Edla at the ironmaster's house, ultimately chose not to run away with the stolen money.
Step 2: Content of the Letter:
He left a letter addressed to Edla, signed 'Captain von Ståhle', thanking her for treating him like a captain rather than a thief — for seeing and honouring his human dignity. He returned the stolen money, and as a Christmas gift, left her the rattrap itself, saying he wished to give her something valuable to remember him by, since she had shown him kindness when the whole world had treated him only with suspicion.
Final Answer:
The peddler's letter, signed 'Captain von Ståhle', thanked Edla for treating him with respect and honouring him as a human being rather than judging him as a thief; he returned the stolen money and left her his rattrap as a Christmas present, in gratitude for restoring his faith in human goodness.