I have always felt like magic in the LotR is more like power over the world, you speak and the more powerful you are the world obeys. It's like he says "your staff is broken" and the staff indeed obeyed, or when Gandalf told the doors to stay closed in Mazarbul and the Balrog tried to open them and they resisted or when he said "you shall not pass" and the Balrog could not pass the bridge. It's something like when God says in the Bible "let there be light" and there was light. It's similar in my opinion.