O Lamm Gottes, unschuldig (3 versus) BWV 656

Whose song is O Lamm Gottes, unschuldig (3 versus) BWV 656?

Artist Album
Bach, Johann Sebastian
Foccroulle, Bernard - Silbermann Orgel, Dom Freiberg ; ...
Gerhard Weinberger (Silbermann Organ St. Petri Freiberg)
J.S. Bach - Organ Works Vol. 2