Kirnberger must have really loved the melody “Wer nur den lieben Gott lässt walten”, as there are at least four pieces by his hand based on this melody (including this one).
This version was first published in the 1790 edition of Johann C. Kühnau. It is marked as meant for ‘two manuals and pedal’. But that’s probably an error, because what is notated as bass voice is not easily played with the feet. However, it is possible to move the voices a bit around. I play the choral melody with the feet on a 2′ stop, the bass voice with the left hand and the alto voice with the right hand. Both a manualiter version of the score, and the version I recorded are available as download on partitura.org