Washington Irving, "The Legend of the Two Discreet Statues" (1832/1851) from Washington Irving: Bracebridge Hall, Tales of a Traveller, The Alhambra:
Washington Irving has left a popular legacy two-stories wide, both of which have a supernatural element and so get taught first to kids. I mean, I think I read "Sleepy Hollow" and "Rip Van Winkle" sometime in elementary school, which is useful, since the basic tropes/images get reused a lot, in everything from cartoons (hello, Ducktales, you insatiable repackager of previous stories) to Belle and Sebastian songs. But that's about all we learn. Irving's other literary works, his international life and consular work in Europe, his attitude towards the Old World and Britain--all that is obscured by a headless horseman and a sleeping man.
So part of me wonders if this story got chosen as a way to bridge that gap: while we have an Old World setting--Irving was reportedly very interested in the Alhambra when he was in Spain--we also get a very folksy supernatural tale, and this one even involves a cursed ride, similar to "Sleepy Hollow." Or rather, we get two folksy tales. The first is the story of a good girl who finds a trapped Christian woman who has to play for the evil Muslim sorcerer who caught her; but on this one holiday, the trapped woman can leave and shows the girl where some treasure is, which is at the point where two statues point. Then, the second story is how dad gets the treasure and has to sneak it out before this greedy monk steals it all away. The monk knows about it because the poor man's wife confessed about it; and when she tells the monk the husband is sneaking it out of an area often considered cursed, the monk goes there and finds himself on a cursed donkey, chased by a pack of demonic dogs.
It's so Irving-y, that I wonder why this story doesn't get more play, both in school and in the wider culture. Is it because of the ambiguous depiction of religion? Knowing some of the anti-Catholic and anti-papal sentiment in the Anglo-American world, I can see how Irving would feel comfortable with this venal and hypocritical monk; whereas today, people might feel a little more uncomfortable about that. (Though the answer to this sort of worry is usually the same: if you don't want to be seen as arguing that all X are something, bring in some X who isn't. If I was adapting this for a movie, I'd consider adding in a sincere monk.) Oh, and, yeah, there's the whole "evil Muslim sorcerer who keeps a white woman as a slave."
There's also a little ambiguity around the poor man who is the protagonist of the second half. He's got many admirable qualities--he's funny and clever, and, in an epilogue, he's shown to be generous with his wealth. But that epilogue is almost necessary because he's pretty self-centered and greedy throughout. Yes, we may sympathize with a man who suddenly has to worry about theft (whereas he was too poor before); but the solution to that worry might just be to be generous with his other poor friends. That said, I think this argument doesn't totally work, since both "Sleepy Hollow" and "Rip Van Winkle" have pretty ambiguous protagonists: we remember Ichabod Crane as a hero, but he's anything but heroic; and Rip's whole character is that he wants to sleep and get away from his nagging wife. Irving rarely writes aspirational protagonists.
Perhaps the answer has also to do with the depiction of women here, where the moral seems to be that women can't keep secrets: the statues are discreet only because no one is paying attention to the fact that they are also literally pointing at the secret; the little girl learns of the treasure from a woman; the dad learns about it from the little girl (who naturally grows up to be married off); and the monk learns of it from the wife. "Gossipy women" might join "nagging wives" as a recurring motif of Irving's.
Finally, let's be totally honest: we teach Irving as this arch-American writer, so--along with forgetting his international, diplomatic life and interest--we focus on his American-set folk-stories.