Messiaen actually wrote this piece for orchestra in 1926 before transposing it to the organ. The text from the Gospel is transposed into mystical music, which is primarily intended for the Feast of Corpus Christi, but is also often played at communion.
The piece begins with floating stops (Voix Céleste, Gambe, Bourdon 8') with the swell almost closed, which is then gradually opened. The pedal introduces the mystical main theme in staccato with a carillon registration (4', 2 2/3', 2', 1'), symbolising the drops of blood that become fewer and fewer. The work is concluded with the floating stops and a 32' labial stop in the pedal.