An oasis, in spiritual terms, represents refreshment and the idea of being able to put difficulties to one side for a time. Most people see an oasis as a place of refuge in a desert. Because of its association with water, in dreams it becomes a place where we can give and receive whatever emotional refreshment is required. When people are in difficulty, they need a place where they can express themselves or perhaps renew their own strengths and ability to cope. In dreams, an oasis, particularly when we are lost, represents such a place. It highlights a particular type of sanctuary. You might also like to consult the entries for Desert, Lose/Loss/Lost and Water.