After serving in this office for ten years, he abdicated, hoping to pursue a life devoted to study and asceticism.
His "Excerptum Speculi Caritatis" is a verse adaptation of the "Summa Causum" of Raymond of Peñafort.
Arnulf is also the probable author of the Membra Jesu Nostri, a cycle of seven poems, each a meditation on one of the wounds of the crucified Christ.
In the 17th century, Paul Gerhardt wrote an adaptation in German, which became "O Sacred Head, Now Wounded" in English.
The "Membra Jesu Nostri" did appear in Bernard's collected works, but only beginning two hundred years after his death.