Nawab Wazir Khan of Sirhind had felt concerned at the Emperor Bahadur Shah’s conciliatory treatment of Guru Gobind Singh ji. He ordered two of his trusted men with murdering the Guru before his increasing friendship with the Emperor resulted in any harm to him. These two pathans Jamshed Khan and Wasil Beg pursued the Guru secretly and overtook him at Nanded, where one of them stabbed the Guru in the left side below the heart as he lay one evening in his chamber resting after the Rahras prayer. Before he could deal another blow, Guru Gobind Singh struck him down with his sabre, while his fleeing companion fell under the swords of Sikhs who had rushed in on hearing the noise.

As the news reached Bahadar Shah’s camp, he sent expert surgeons, to attend to the Guru. The Guru’s wound was immediately stitched by the Emperor’s European surgeon and within a few days it appeared to have been healed. The injury had been contained and the Guru had made a good recovery.

Some Karigars from Hyderabad came to guru sahib and gave shastars to guru ji. Someone requested to Guruji to tug the arrow and make his fullfill true. Guru Ji was not fully improved, but to fulfill his wish, when the Guru tugged at a hard strong bow, the imperfectly healed wound burst open and caused profuse bleeding. It was again treated but Guru knew that heaven has called.

He then opened the Granth Sahib, placed five paise and solemnly bowed to it as his successor. Saying ‘Waheguru ji ka Khalsa, Waheguru ji ki Fateh’, he walked around the Guru Granth Sahib and proclaimed, “O beloved Khalsa, let him who desireth to behold me, behold the Guru Granth. Obey the Granth Sahib. It is the visible body of the Gurus. And let him who desires to meet me, search me in the hymns.” Guru Ji then set his on pyre (Angeetha). Next day, guru ji entered in closed structure in which pyre was establihed. The Flames were rising high. Bhai Daya singh went inside to check angeetha, there was nothing but a Small Kirpan in angeetha. So everyone accepted that Like Guru nanak Dev, Guru Gobind Singh also went to Sachkhand with his body.

 

Reference:

http://www.indianage.com/search.php

http://www.sikhiwiki.org/index.php/Death_of_Guru_Gobind_Singh