What is the author is trying to tell us?
The author trying to tell us a couple of things through this story. For one thing, the subtitle is "A Tale for Children." This shows how it's in a fairy tale format. That explains the magical elements and allows the reader to accept what he reads rather than question it. As for morals there could be three told through his story: "most people wouldn't know a miracle if the saw one;" "patience will always pay off"; and "appearances may not always be as they seem."
Miracles could have occurred during his stay there. Their child's health improves. The rain stopped. Even the old blind man sprouts new teeth, even though he didn't get his sight back, those things could be considered miracles.
Patience is obvious in his suffering through the circus-like environment and his horrible living conditions.
The old man appears dirty, old and about to do, yet he flies off in the spring. Just because such gifts don't come with big red bows doesn't mean they're not gifts.