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.  

كُنَّا نَغْزُو مَعَ النَّبِيِّ ﷺ فَنَسْقِي الْقَوْمَ وَنَخْدُمُهُمْ وَنَرُدُّ الْجَرْحَى وَالْقَتْلَى إِلَى الْمَدِينَةِ