Jundub bin Sufyaan Radiyallahu 'Anhu relates:
"Once a stone hit the Mubaarak fingers of Rasulullah Sallallahu'Alayhi Wasallam and injured them, they became covered in blood. Rasulullah Sallallahu'Alayhi Wasallam thereupon recited this couplet: 'You are but a finger, no damage has overcome you, besides covering you in blood. This is not fruitless, for reward has been obtained in the path of Allah'". (FR)
English reference (FR): Book 36, Hadith 233 (FR)
Arabic reference (FR): Book 37, Hadith 243 (FR)