We've reached the appendix of the Breitkopf edition of Walther's chorale preludes. This is the first of three works in the appendix.
According to the critical notes, this prelude appears in the appendix apparently due to its omission in Walther's own manuscripts and its appearance only in a later manuscript of unidentified origin, and some stylistic concerns that make it difficult to ascertain Walther's authorship with sufficient certainty to be included in the main body of chorale preludes.
The two verses are for two contrasting manuals and pedal with the cantus firmus in the pedal. The second verse is notable for the chromaticism displayed in the opening bars.