The Fisher and the Little Fish

It happened that a Fisher, after fishing all day, caught only a little fish.  "Pray, let me go, master," said the Fish.  "I am much too small for your eating just now.  If you put me back into the river I shall soon grow, then you can make a fine meal off me."

"Nay, nay, my little Fish," said the Fisher, "I have you now. I may not catch you hereafter."

A little thing in hand is worth more than a great thing in prospect.