"The Ancient Law Departs"

A couple years ago, I noticed a small feature in "The Ancient Law Departs" (in the New Year section of LSB).  The hymn is sung to the tune "Potsdam"; here are the first two musical phrases:

In the fourth verse, the text here is "Today the name is Thine / At which we bend the knee."  As if to reflect this "bend[ing] the knee," the end of that phrase descends (from Eb to Bb).

"Potsdam" (TLH #135)

"Potsdam" (TLH #117)

Because this is a shorter tune, I went through it three times.

"Potsdam"

Bach's birthday is later this week (21 March), so I thought I'd do one of his tunes.  LSB says that "Potsdam" is adapted from something he wrote (although it doesn't say specifically what), so I decided to do that.  However, it's in different keys in LW (D major) and LSB (Eb major).  I transposed the LSB arrangement down a half-step.  I had to change the last note though because I can't play a low F# on mandolin (it goes down only to G).  I made that into an A so there's still something of a resolution.