Complex sentence: The final line is in free polyphony, extended even during the long last note of the tune, all voices have extended melismas on the word "walten" (govern), stressing that God is "ultimately in control".
Split into simpler sentences: The final line is in free polyphony, extended even during the long last note of the tune. All voices have extended melismas on the word "walten" (govern), stressing that God is "ultimately in control".