(71) باب فَضْلِ الْخِدْمَةِ فِي الْغَزْوِ
Narrated Anas:
We were with the Prophet (on a journey) and the only shade one could have was the shade made by one's own garment. Those who fasted did not do any work and those who did not fast served the camels and brought the water on them and treated the sick and (wounded). So, the Prophet (ﷺ) said, "Today, those who were not fasting took (all) the reward."
Reference: Sahih al-Bukhari 2890
In-book reference: Book 56, Hadith 105
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 4, Book 52, Hadith 140