Where does the story of sour grapes come from if you can't eat grapes?

The fox came to the prairie and found that the vines were covered with strings of crystal clear grapes. He wants to eat them very much. But the vines are too high to reach. He jumped into the tree to catch it, but he still couldn't catch it, which made a mess. Seeing that it could not be picked many times, both rabbits and deer laughed at its incompetence. The fox, tired and ashamed, panted, "This grape is not ripe yet. It must be sour and not delicious. " As he spoke, he walked home in frustration and comforted himself: "This grape is not ripe yet, it must be sour."

The story is like this. Some people are weak and incompetent, and they just make excuses to cover up their incompetence.

This is the origin of "you can't eat sour grapes".

The story comes from Aesop's fable The Story of the Fox and the Grape.