Herz und Mund und Tat und Leben ("Heart and Mouth and Deed and Life") is a cantata by Johann Sebastian Bach. In Wolfgang Schmieder's catalogue of Bach's works, it is BWV 147. It was written in Leipzig for the Visitation of the Blessed Virgin Mary, and was first performed on 2 July 1723. Much of the music of Herz und Mund und Tat und Leben comes from Bach's Weimar period.
