We used to take part in holy battles with the Prophet (ﷺ) by providing the people with water and serving them and bringing the killed and the wounded back to Medina.
Sahih al-Bukhari Book 56, Hadith 98
← Previous Hadith We were in the company of the Prophet (ﷺ) providing the wounded with water and treating them and bringing the killed to Medina (from the battle field) .

Sahih al-Bukhari Book 56, Hadith 97 Next Hadith → Abu 'Amir was hit with an arrow in his knee, so I went to him and he asked me to remove the arrow. When I removed it, the water started dribbling from it. Then I went to the Prophet (ﷺ) and told him about it. He said, "O Allah! Forgive `Ubaid Abu 'Amir."

Sahih al-Bukhari Book 56, Hadith 99