If I have to say the truth I don't know this sentence, and probably it is not a proverbial sentence. In the common meaning however the fox is the nature representation of smart and adaptable animal. The meaning of the sentence could be: it would have been better if your god had offered protection to a smart person (instead you ?)
Sentence that sound pretty offensive :)
Btw, the wolf is another and more complex figure. It is bad, wild and often used in the proverbial sentences. In the sentence: in bocca al lupo
the mean become from the hunters, and people that meet them before going into the wild. The people say: if you have to meet a wolf (evil) I hope that you meet it face by face (so you can kill him).
The same is for: in culo alla balena. Because if u, fisherman, want to catch a whale, you have to meet it from the back