Eliezer tells the story that elaborates on why you should be careful what you wish for. Of about a dozen versions of the Eagle and Tortoise story I've just skim-read, none of them really has this as a moral - in each of them, either the Eagle or a Tortoise was an asshole and/or liar and/or lying asshole, so the more valid moral would be, "don't deal with dangerous people" and/or "don't be an asshole" and/or "don't be an asshole to people who have power to hurt you".