Al-Imām al-Bukhārī - upon whom be mercy - narrates: Mālik ibn Ismā’īl narrated to us; he said: Isrā’īl narrated to us from ‘Āṣim,
from Ibn Sīrīn, who said: I said to ‘Ubaydah: We possess a hair of the Prophet ﷺ, which reached us from Anas ibn Mālik (may Allāh Almighty be content with him), or from the family of Anas. Thereupon he said: If I were to possess a single hair of the Messenger of Allāh ﷺ, it would be more beloved to me than the entire world and all that it contains.
Reference: Sahih Al Bukhari 170