First Paalki Sahib in which Bahi Mohan Singh ji brought Gurbani Pothis

Guru Arjan the Fifth Sikh Guru compiled the original version of the Guru Granth Sahib. The Guru’s older brother Prithi Chand as well as others had started passing off some of his own compositions as the hymns of the Gurus. Guru Arjan realized that if this situation was allowed to continue it would be the undermining of the Sikh religion. The Sikhs needed an authentic compilation of the hymns of their Gurus. Thus Guru Arjan started collection the original verses of all the Gurus. He sent trusted Sikhs such as Bhai Piara, Bhai Gurdas and Baba Buddha across the country in search of original manuscripts. Guru Arjan made trips to Goindwal, Khadur and Kartarpur to visit the families of the previous Gurus. Guru Arjan collected original manuscripts of the Gurus from Mohan (son of Guru Amar Das), Datu (son of Guru Angad) as well as Sri Chand (son of Guru Nanak).

Guru Arjan now pitched a tent by the side of Ramsar tank in Amritsar and started the arduous task of compiling the first edition of the Holy Guru Granth Sahib. Bhai Gurdas was entrusted as the Guru’s scribe for the master copy. The monumental task was finally completed after a number of years. This original edition of the Guru Granth Sahib known at that time as Pothi Sahib was installed on a high pedestal within the Harmandir Sahib in August 1604. Guru Arjan seated himself at a lower level and instructed all Sikhs to bow before it, not as an idol, but as the book of divine inspiration which instructed living men in the ways of God and dedicated secular life. The revered Baba Buddha was appointed the first Granthi (custodian) of the book. Guru Arjan dictated that unlike the Hindu scriptures, the Pothi Sahib could be open to reading by anyone of any caste, creed or sex.

~ Source: http://www.sikhs.org/