Cantata no. 157: Ich lasse dich nicht, du segnest mich denn, BWV.157

Ich lasse dich nicht, du segnest mich denn (I will not let you go, unless you bless me), BWV 157, is a church cantata by Johann Sebastian Bach. He composed it in Leipzig in 1726/27 to a libretto by Picander. The first known performance was on 6 February 1727 during a memorial service for Johann Christoph von Ponickau in Pomßen near Leipzig. The work was later assigned to the feast of the Purification celebrated on 2 February.

Picander included a quotation from Genesis 32:26–32 in the first movement, and the last stanza of Christian Keymann's "Meinen Jesum laß ich nicht" in the closing chorale. The contemplation begins with the Old Testament quotation being applied to Jesus, and leads to the last aria expressing an eager wish for death to arrive soon. The closing chorale picks up the first line.

Bach structured the cantata in five movements. The original "chamber music" version (as reconstructed by Klaus Hofmann) was scored for two vocal soloists, tenor and bass, a four-part choir, and a Baroque instrumental ensemble of flauto traverso, oboe d'amore and continuo. In the later version, there are parts also for oboe, two violins and violetta.