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. (Using translation from Bukhārī 2883)
كُنَّا نَغْزُو مَعَ رَسُولِ اللهِ ﷺ فَنَسْقِي الْقَوْمَ وَنَخْدُمُهُمْ وَنَرُدُّ الْجَرْحَى وَالْقَتْلَى إِلَىالْمَدِينَةِ