Jamieson, Fausset and Brown on Deuteronomy 8:7

7. For the Lord thy God bringeth thee into a good land--All accounts, ancient and modern, concur in bearing testimony to the natural beauty and fertility of Palestine, and its great capabilities if properly cultivated.

a land of brooks of water, of fountains and depths that spring out of valleys and hills--These characteristic features are mentioned first, as they would be most striking; and all travellers describe how delightful and cheerful it is, after passing through the barren and thirsty desert, to be among running brooks and swelling hills and verdant valleys. It is observable that water is mentioned as the chief source of its ancient fertility.