George Frideric Handel's autograph manuscript of the title page of Messiah, 1741 (Photo via Wikipedia)
29 The next day John seeth Jesus coming unto him, and saith, Behold the Lamb of God, which taketh away the sin of the world.
Behold the Lamb of God (chorus), from Messiah (1741) by George Frideric Handel (1685-1759)
[Behold the Lamb of God starts at approximately 52:27]
Performed by the Academy of Ancient Music and the Choir of Westminster Abbey, with conductor Christopher Hogwood
Messiah, Edited by Watkins Shaw, Novello Handel Edition. 257 pages
FREE SHEET MUSIC
Choral Public Domain Library