Here is a well-known proverb in Italian, with a near-equivalent in English.Predica bene e razzola male. Literally, he/she preaches well and acts badly. They don't practice with they preach. The fact that this saying is so widespread in the two languages shows that the behavior is universal and timeless.
The verb razzolare actually means to scratch on the ground, as chickens do (if they're free-range chickens). It's rarely used, and it's likely that you'll encounter it only in this proverb.
(in the picture, Moliere's Tartuffe, the symbol of religious hypocrisy)
