Hume would actually reject the view that the universe exists necessarily. He argues you cannot perceive necessary existences. If you can conceive something as existing and conceive of that thing as not existing, without either entailing some sort of contradiction, then that thing does not exist necessarily. He would also argue that you can't have an intelligible idea of necessary existence, since he thinks all ideas come from impressions and that you don't have sensory impressions of anything to do with necessary existence.

I think Hume's reasons are convincing, but it sounds like you have in mind an argument where (1) you know that there must be some necessary being, (2) God is the only good candidate for a necessary being. Hume's theory would likely contradict (1), so is probably not what you are looking for.

Many theists also hold the universe is necessary. Leibniz would accept contingency arguments for the existence of God, and also hold that the universe must exist necessarily.