Abdu'l-Baha', was sad on one occasion because he had learned of an incident of backbiting among the friends and said:

"I don't know where the people have learned the art of backbiting?" 

A Baha'i believer answered, 'Beloved Master, from God himself.' 
The Master said, "How?"

The Baha'i answered, 'Adam ate one apple only in his whole life and God mentioned it to everyone in the Old Testament, in the New Testament, and in the Qur'an........'

(From A Seminar conducted by the Hand of the Cause of God A. Q. Faizí in Hawaii in 1967).