The Swallow and the Other Birds

It happened that a Countryman was sowing some hemp seeds in a field, where a Swallow and some other birds were hopping about picking up their food. "Beware of that man," said the Swallow. "Why, what is he doing?" said the others. "That is hemp seed he is sowing; be careful to pick up every one of the seeds, or else you will be sorry." The birds ignored the Swallow's words, and by and by, the hemp grew up and was made into string, and of the string, nets were made, and many a bird that had ignored the Swallow's advice was caught in nets made out of that very hemp. "What did I tell you?" said the Swallow.

And, the moral is.

Destroy the seed of evil, or it will grow to be your ruin.