"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).