GOPI MAHITA, BHAI, accompanied by Bhai Tirath, Bhai Nattha, Bhai Bhau Mokal and Bhai Dhilli Mandal, once visited Guru Arjan. One of them, as says Bhai Mani Singh, Sikhan d~i Bhagat Mala, said: “Lord, Prithi Mall and Mahadev [the Guru`s brothers] are also composing verses using the name of (Guru) Nanak as nom de plume which makes it difficult to know the genuine from the counterfeit.” The Guru, addressing himself to Bhai Gurdas, spoke: “Today there are many Sikhs who know which are the true compositions of the Gurus, but tomorrow there may be none. The hymns of the Gurus should therefore be collected and compiled into a single volume.

You may straightway start working with what is available here in our household, and arrange to procure what is not. Use the Gurmukhi script in your transcription.” It was in this way that the Guru Granth Sahib came to be compiled (Varan, XI. 2 6).

References :

1. Mani Singh, Bhai, Sikhan di Bhagat Mdla. Amrilsar, 1955
2. Santokh Singh, Bhai, Sri Gur Praia? Suraj Cranlh. Amritsar, 1927-33