Explanation:

Pir Budhu Shah was a Muslim saint who lived at Sidhaura in Himachal Pradesh. His original name was Sayyid Badr-ud-din. He was born on June 13, 1641, in a rich Sayyid family of Sadhaura. From his childhood he was imbued with spiritualism and realization of God.
While Guru Gobind Rai was staying at Paonta, the Pir was touring the hilly areas. The Pir came to know that Guru Gobind Rai, the tenth embodiment in the line of Guru Nanak, was staying at Paonta. He went to see the Guru, in a palanquin, as it was the fashion among kings and emperors of those times to move with royal pomp and show, in palanquins, with attendants and servants.
After the war of Bhagnani was over, the Pir came to take leave from the Guru to go back to Sidhaura. The Guru asked the Pir, “You have rendered great help to me in this war. You may ask if you have any special wish. Your wish will be fulfilled from the ‘House of Nanak’.” At the time, the Guru was combing his hair. The Pir said to the Guru, “If you are so pleased with my services, be kind enough to grant me this comb with your hair entangled in it.”

The Guru gave the comb with the hair to Pir Budhu Shan. Later on Maharaja Bharpur Singh of Nabha state obtained that comb and hair from the descendants of the Pir after paying the sum asked by them.