Ich lasse dich nicht, du segnest mich denn (I will not let you go, unless you bless me), BWV 157,[a] is a church cantata by Johann Sebastian Bach.
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 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.
[2][3] A printed commemoration sermon survives, with some information about the music performed[3] which included a second Bach cantata, the now lost Liebster Gott, vergißt du mich, BWV Anh.
[1]: 766 For Ich lasse dich nicht, du segnest mich denn, Picander included a quotation from Genesis 32:26–32 in the first movement, but the line from Jacob wrestling with the angel is understood as a believer addressing Jesus.
[3][4] The cantata appears to have been adapted for performance as part of Leipzig's church music, specifically for the Feast of the Purification of Mary celebrated on 2 February.
[2] Bach structured the cantata in five movements, and scored it for two vocal soloists, tenor (T) and bass (B), a four-part choir only in the closing chorale, and a Baroque instrumental ensemble.
The opening movement sets a single line: the biblical quotation from Genesis which became the title of the cantata: "Ich lasse dich nicht, du segnest mich denn" (I will not let you go, unless you bless me).
[1][7] The movement has an eight-measure ritornello that opens, ends and bisects it, featuring a prominent imitative motif to the words "Ich lasse dich nicht".
According to Julian Mincham, "these details serve to remind the modern listener, armed with a score, of Bach's integrated approach to cantata architecture".
The cantata ends with a four-part setting of the chorale, "Meinen Jesum laß ich nicht, geh ihm ewig an der Seiten" (I will not let go of my Jesus, I will walk beside Him forever),[7] with a conjunct melody and active continuo line.