During the battle of Uhud, Rasulullah (sallallahu ‘alaihi wasallam) was severely attacked by the enemy and two links of his helmet penetrated his mubaarak face.
Hazrat Abu Bakr Siddeeq (radhiyallahu ‘anhu) and Hazrat Abu Ubaidah (radhiyallahu ‘anhu) immediately ran to assist Rasulullah (sallallahu ‘alaihi wasallam). Hazrat Abu Ubaidah (radhiyallahu ‘anhu) began pulling out the links with his teeth. By the time one of the links was removed, he had lost one of his teeth. Not regretting the loss of his tooth, he again used his teeth to pull out the other link as well. He succeeded in removing the other link, however in the process, he lost another tooth.
When the links were drawn out, the blood began to ooze out from the body of Rasulullah (sallallahu ‘alaihi wasallam). Hazrat Malik bin Sinaan (radhiyallahu ‘anhu), the father of Hazrat Abu Sa’eed Khudri (radhiyallahu ‘anhu), licked the blood with his lips. At this, Rasulullah (sallallahu ‘alaihi wasallam) remarked, “The fire of Hell cannot touch the person who has my blood mixed with his.” (Musnad Abi Dawood Tayaalisi #6 & Fathul Baari 7/366)