The Arul Nool is a supplement to the Akilattirattu Ammanai, and is likewise considered a holy scripture of Ayyavazhi. This book contains the collection of messages given by Ayya Vaikundar to his Disciples, whose names are unknown. Since they are believed to be composed by Arylalarkar, it acquired the name Arulnool. There is no direct indication within the book regarding the time of its composition.