It's an expression of surprise, like gee. It is usually to liking or satisfaction. It's an over-the-top way of saying "Well be God and the Virgin." It can also reflect scare or disgust and means For God's sake! .
BENAIGA In Chile : campechana way of saying Bless it! Contraction derived from Good and Hague : that there is good . It is commonly used with the meaning of "good thing"