Bhai Kahn Singh Nabha Was a celebrated scholar and encyclopaedist. His most influential work,Mahan Kosh, inspired generations of scholars after him. He also played a role in the Singh Sabha movement. His books Gurmat Prabhakar and Gurmat Sudhakar are the standard guide books for understanding Sikhism.His work Gur Shabad Ratankar Mahan Kosh is the magnum opus.