The Quack Frog Lyrics

A Frog once made proclamation to all the beasts that he was a learned physician, and able to heal all diseases.

A Fox asked him: "How can you pretend to prescribe for others, and you are unable to heal your own lame gait and wrinkled skin?" 

Moral : Those who pretend that they can mend others should first mend themselves, and then they will be more readily believed.