Moissonneur buvant a la gourde ou la Soif Leon Augustin Lhermitte (1844-1925)

The picture has something of this: mammal, people, cavalry, skirmish, war, soldier, landscape, military, outdoors, two, group, desert, tree, grassland, army.
Perhaps it’s a painting of a group of people working in a field with a horse and a plow in the foreground and a tree in the background.