This letter is duplicated in the 15th volume of Walch's old edition, namely No. 663 and here. Because we have already included it there, we leave it out here.
Complete Luther Library
Luther to Caspar Güttel.
Volume 15 from the one-column St. Louis Edition English DOCX texts, reformatted for mobile reading on Last Christian Ministries.
Source text used with permission from Back to Luther.