Ein Herz, das seinen Jesum lebend weiß (A heart that knows its Jesus is living), BWV 134, is a sacred cantata for Easter by Johann Sebastian Bach, written for the third day of Easter in Leipzig and first performed it on 11 April 1724. He based it on his congratulatory cantata Die Zeit, die Tag und Jahre macht, BWV 134a, first performed in Köthen on 1 January 1719.
