As with most folklore there are variations on this story, but this is the basic tale–a poor but kindly old couple more or less adopt a sparrow because they like to hear it singing. A bad-tempered neighbor doesn’t like the sparrow at all, because it wakes her up in the morning. So she decides to catch it and split its tongue so it can’t sing anymore. This she does, and the maimed bird flies away. In sorrow, the old couple go looking for the bird, but when they follow in the direction it flew, what they find is a magnificent mansion where they are warmly greeted by a man who identifies himself as the sparrow. This is not so strange in context since, in Japanese folklore, almost all animals were thought to be shapeshifters. Regardless, the old couple are treated to great hospitality. When they are ready to leave, the sparrow offers the couple their choice of two baskets as gifts. One is small and light, the other rather large and heavy. Still in sorrow for what happened to their friend and not wishing to impose on his generosity, they pick the small basket. Once they return home, they discover that the basket is magic, and will produce whatever they wish: rice, cloth, even gold. The poor old couple are no longer poor. The bad-tempered neighbor, seeing their good fortune, asks how they came by the basket and they tell her. At this point the neighbor resolves to visit the sparrow herself.
Ok, anyone not in the story would have to wonder just what sort of delusional thought process would lead a person to think “Well, I did this bird a great wrong out of spite, but surely it won’t hold a grudge and will, at least out of politeness, reward me also.” Oddly enough, the neighbor appears to be right in this. She comes to the sparrow’s home and is also greeted warmly, and later given the same choice of baskets as a parting gift. Being the ill-mannered and greedy sort she is, she chooses the big one, which is full of devils and biting insects, and just about every nasty thing one might expect, and so she gets her “just reward.”
The significance I leave to others, if anyone’s so inclined. The old neighbor’s reason for maiming the sparrow was straightforward: it was singing early every morning and waking her up, which annoyed her. She cut the sparrow’s tongue so that it could no longer sing. I don’t know of any cultural significance or tradition having to do with slit tongues, except while growing up in the South I heard an oral legend that, if you split a crow’s tongue, it would be able to talk. Fortunately for the crows, I don’t know of anyone who tried this.
Now, about that “just reward” thing–I’ve heard “The Tongue-Cut Sparrow” described as a “revenge tale,” but I don’t agree. I think that interpretation leans too heavily on Western cultural assumptions. On closer examination, it’s nothing of the sort. Absolutely nada happens to the bad neighbor as a direct result of her maiming the sparrow, nor did the sparrow take any overt action to seek revenge. Everything that happens to the neighbor she brings on herself, and is due to her own bad nature which, if you’re into irony, was what led her to maim the sparrow in the first place. You’ll note that the sparrow treated the wicked neighbor with exactly the same hospitality as it did the kindly old couple. It also gave the exact same choice to the wicked neighbor as it did to the kindly old couple, and the kindly couple chose wisely and with good will, as the neighbor did not. If the bad neighbor hadn’t let her greed get the best of her, she’d have been rewarded too, despite what she did to the sparrow. But then, of course, she wouldn’t have been acting according to her own nature. Actions may have consequences, but who and what we are drives our actions.
Or, to put it more succinctly – Karma is not fate. Karma is a debt, and it always collects.