The story is told in Genesis 16. The servant girl Hagar became pregnant by Abraham. She quarrelled with Abraham's wife Sarah, who was childless, and ran away. An angel met her by a spring in the wilderness. He told her that the child, Ishmael, would found a great tribe. Meanwhile she should return to Sarah (he points the way).
Claude composed this picture on principles of landscape construction developed earlier in the 17th century by Annibale Carracci and Domenichino. This uses a balanced composition, often with trees as a frame at the edge. Buildings are stabilisers (verticals) and distance markers. The foreground often includes figures from a story. The viewpoint is less elevated than that usual in, for example, 16th-century Flemish landscape. The individual items in classical landscape are based on observation, but their selection and ordering within the picture tended to improve on nature.
This work, much admired by Constable, was the favourite of Sir George Beaumont. When he gave his collection to the Gallery he asked to keep this painting until his death.