The story of Khalid and the Blessed Hair !
Once Khalid Ibn al-Walid lost a headgear (qalansuwah) that Muslims wear on their heads like a hat, and he wore during a Battle called the Battle of al-Yarmuk. He asked the people to help him find it and they searched but could not find it!
Then he asked them to search repeatedly until it was found. They saw it was a very old qalansuwah and thought it strange that Khalid Ibn al-Walid was so insistent on finding it, that he asked the army to find it!!.
Khalid Ibn al-Walid told them: "Prophet Muhammad performed ^Umrah (in Makkah) and then shaved his head. I rushed with the people to get some of his hair. I got some of the hair from the front part of his head which I put in this qalansuwah. Every time I went into battle with this qalanswuwah, Allah gave me victory."
Khalid Ibn Walid, was a great Companion who sought the blessings from the Prophet's hair--hoping by this Allah would give him victory in his battles. He was a great, brave hero, and he never lost a battle after that.
This is a true story, that happened to a great companion that used to love Allah and Prophet Muhammad peace be upon him. Look how Allah blessed Khalid and his army, by the blessings of the Prophet and they never lost a battle after this!
This is a proof that the companions used seek blessings by the traces of the Prophet like his hair and clothes, and so Muslims until today are blessed by the touching the blessed hair of the great Prophet (peace be upon him).
(This story is confimred and narrated al-Bayhaqiyy in his book Dala'il an-Nubuwwah with a authentic Sahih chain).